Optically active composition and light-emitting combined device based on said composition

FIELD: physics.

SUBSTANCE: described is novel assembling of semiconductor devices combined with optically active compositions. In particular, light-emitting semiconductors based on an InGaN structure, combined with highly efficient optically active langasite crystals La3Ga5SiO14. When activating the langasite, said composition interacts with radiation of the InGaN structure. The langasite absorbs high-energy photons emitted by the InGaN structure, and re-emits light with longer wavelength. Short-wave, high-energy radiation of the InGaN structure is mixed with longer wavelength radiation of the optically active composition and forms a wide spectrum which is perceived by a viewer as white light.

EFFECT: design of a wideband light source based on semiconductor structures, where a langasite photoluminescent phosphor with high radiation excitation efficiency, characteristic of InGaN light-emitting diodes, re-emits light in the middle range of the visible spectrum.

19 cl, 4 tbl, 2 dwg

 

The technical field to which the invention relates.

The present invention relates, in General, to a special optically active compositions and combination devices, combining the composition and light-emitting elements, and more particularly to a combined light-emitting devices containing optically active composition based on Langasite in combination with LEDs emitting in the shortwave region of the spectrum.

Description of the prior art,

Created a relatively new material, known as Langasite or more precisely "latinogay silicate", has found its application in new inventions thanks to its special properties. The subject of new inventions is not only the technology of Langasite, new inventions were created through the use of special physical properties that have demonstrated this class of materials.

The following important inventions describe the various technologies for Langasite in a form suitable for wide use.

The invention is for My, and others, called "Langasite Crystals and their method of manufacture", issued by the US patent 6303048. In this invention, the melt containing lanthanum oxide, tantalum oxide and gallium oxide, is prepared by mixing powders of these oxides in such a way as to have the tre is been created stoichiometric value of the composition to obtain the desired lanthanum oxide/tantalum/gallium. The seed crystal is placed in the melt and a large crystal pulled from the melt in an atmosphere containing argon and oxygen, as described in the Czochralski method.

Monocrystalline substrate of Langasite can be obtained by using the invention Kumatoriya and others described in the patent US 6525447. Monocrystalline substrate is used as the piezoelectric device. More specifically, in the invention described sequential steps for polishing at least one of main surfaces of the unprocessed substrates and a liquid etching polished main surface of the substrate solutions, including H3RHO4, HNO3and CH3COOH.

Crystalline materials of Langasite can be used in electronic devices as generators or filters, in particular for the management of radio frequencies.

In published patent application US 2002/0015452 inventors Chai and others introduced an electronic device including a connection structure of Langasite and method of manufacturing such a device. The piezoelectric layer is formed of connections ordered Langasite structure having the formula A3BC3D2E14where a Is Strontium, Niobium, Gallium, D is Silicon, and E Is Oxygen. Such devices can operate in ka is este resonators or filters, surface or bulk acoustic waves.

Also the device on surface acoustic waves containing crystalline substrate Langasite, was presented by the inventors Takeuchi and others in the patent US 6285112. The structure of the substrate and the electrode formed on the substrate Langasite, which represents a cut Langasite single crystal in the direction of the X axis, the rotated slice in the Y axis direction of the Langasite single crystal or a slice in the Y axis direction of the Langasite single crystal with double rotation. The electrode structure is formed to create a filter, surface acoustic waves, having a small insertion loss and excellent phase properties. This device achieved a precision level of frequency control.

The following invention is also intended for frequency regulation, control and filtering.

The invention Gerlach and others at the number of US 6747573 describes a device and method for generating coded high-frequency signal. The device has a Converter, which converts primary energy non-electric origin from the environment into electrical energy. This invention is associated with very important principles, namely the Langasite is used in the processes of energy conversion from one state to another.

Inventors Steve Beaudin and Hongwei Xu Nortel Networks, Ottawa, Canada described the generator with improved h is frequency stability. The device works by using Langasite. Two generators produce signals at two different frequencies, each of which depends on such parameters as temperature, in accordance with a polynomial in which the coefficients are different for the two generators. The mixer generates an output signal at the sum or difference frequency of the two signals, for which the corresponding coefficient in the corresponding polynomial is essentially equal to zero.

The given examples show that the Langasite provides interesting and useful devices of various designs intended for frequency control. The following shows how the Langasite can be used in a completely different way to control the frequencies at much shorter wavelengths. However, before turning to details related with this issue, it is important to pay attention to the description of the prior art that demonstrate some very important principles in the field of frequency management, but which are not associated with a material type of the Langasite. These descriptions include:

Different types of crystals of Garnet (YAG) are used in led systems, the action of which is based on the phenomenon of the shift of the emission wavelength. In one such system the light emitting device on the basis of the nitride semiconductor is of soedinenii considered in combination with the phosphor on the basis of garnet fluorescent material. Such a device is described in patent US 6069440 authors Shimizu and other light-Emitting semiconductor diode in a certain way is covered with a phosphor material that contains fluorescent crystals of Garnet. Light emitted from the p-n junction led out of the semiconductor structure and interacts with the phosphor constituting the Garnet crystals. As a result of interaction of radiation with Garnet crystals, the wavelength is changed. Shortwave radiation is converted into longer-wavelength radiation. Such processes are widely used in systems where it is necessary to convert the blue light in the long wavelength radiation. Such systems are in great demand currently. In the patent US 5998925 the above inventors describes a similar invention and described in more detail all the points.

In the patent US 5962971 author Chen from Taiwan describes the led structure, generating ultraviolet radiation and multilayer polymer that provides the radiation of light of different colors. In the packaging of the led mix of different materials, which may contribute to the change of the wavelength of light in the polymer, which creates conditions for generation of white light led, and light of different colors. These various materials include fluorescent Crist is lly, providing a shift of the emission wavelength, which is applied to the surface of the chip emitting ultraviolet radiation.

Special attention is paid to the LEDs emitting white light. Still the most common designs of LEDs includes a semiconductor structure on the basis of nitrides of group III, which generate blue or ultraviolet radiation, in combination with the phosphor on the basis of yttrium aluminium garnet activated by cerium. In the prior art can be found many patents associated with such a design.

While the system and the invention described above are intended to achieve specific goals, some of which are very significant, at the same time, these same well-known inventions have limitations that prevent their use in possible new directions. Previously known inventions are not used and cannot be used for the realization of the advantages and challenges met by the following invention.

The invention

Abramov B.C., ALEXANDER Shishov, Shcherbakov, NV, Platan research Institute PLC N.P. present invention describing an optically active composition, as well as combined light-emitting devices based on them, containing a light-emitting semiconductor structure. The main purpose of the image is the shadow - to create optically active composition. The main difference from the devices and means described in the prototypes is that the device does not contain expensive yttrium aluminium garnet.

Highly efficient optically active composition based on antanaslietuva silicate La3Ga5SiO14- Langasite. During the synthesis of the composition it is activated by certain elements to change the physical and optical properties that depend on the crystal structure. In particular, can be added in different concentrations of the lanthanides order to obtain certain desired properties of the material. The influence on the optical properties of the compositions is a particularly important element. Activated by lanthanides the Langasite can be used as photoluminous. In particular, you can create a special photoluminous with the spectrum of radiation in the visible region of the spectrum. In addition, the excitation spectrum of the phosphor is well suited for certain applications. The phosphor can be excited by ultraviolet and blue radiation. Additionally it should be noted that the described compositions as the emission spectrum and excitation spectrum are tweakable. The purpose of this invention is to create a broadband light source based on poluprovodn ekovich structures, where photoluminous the Langasite with high efficiency excitation radiation characteristic of InGaN LEDs, pereizuchit light in the middle region of the visible spectrum. This photoluminous is an object of this description of the invention. The best result is achieved when doped Langasite crystal atoms of Cerium, which are introduced into the crystal lattice to form optically active composition. From lanthanides not only the Cerium may be a good activator, other lanthanides allow you to create other interesting examples of photoluminous. The combination of several lanthanides also creates interesting options phosphors.

Variations of the elements of the two groups of metals in the phosphor, namely metals from groups III and IV have had a certain influence on the composition. Some phosphors part of the gallium atoms are replaced by atoms of India. In other examples of the phosphor part of the silicon atoms are replaced by atoms Germany. Possible combinations of these variations. Compositions created in the framework of this invention, are characterized by a crystal structure, which is described as P321(D23). This phosphor material is synthesized so that the average size of the crystals in the phosphor powder was in the range of from 8 to 40 wavelengths of maximum emission spectrum or, in other words the, to the average particle diameter was in the range from 4 to 20 microns. As will be shown, this criterion contributes to the formation of the desired radiation characteristics of the phosphor.

These unique optically active composition very well interact with certain wavelengths. These phosphors are very well excited by radiation with a wavelength lying in the region from 0.1 to 0.45 microns. The use of these phosphor compositions in combination with a special optical system is considered as an integral part of the present invention. In particular, these phosphor materials in combination with InGaN semiconductor structures that emit light in the blue and ultraviolet region of the spectrum, form a highly efficient optical system. Such systems provide for the creation of optical semiconductor sources, emitting white light.

Tasks inventions

The primary objective of this invention is to provide new compositions and crystal structure.

Also an objective of this invention is to provide a new optically active compositions with crystalline structure.

Another objective of this invention is to provide optically active compositions with crystalline structure, suitable for use in systems that use the phenomenon of shift length in the wave radiation.

The objective of this invention is to provide optically active compositions with crystalline structure, which are characterized by the possibility of optical excitation (pumping).

Another objective of this invention is to provide optically active compositions with crystalline structure, which provide not temperature-dependent optical output color beam parameters.

The above and other objectives, features and advantages of this invention will find a more detailed understanding of the following detailed description with reference to the accompanying drawings. Presents the embodiments of the invention are only some particular cases of the implementation of the present invention and does not include all possible implementations of the invention. Thus, there may be implementations of the invention, which correspond to the contents of the description and the claims, but not described in this description as specific examples. Assumes that may be a significant number of additional examples of implementation of the present invention.

Brief description of drawings

The above and other features and advantages of this invention will be more apparent from the following detailed description with the link the th to the accompanying drawings.

1 is a diagram illustrating a light-emitting

the semiconductor device in combination with an optically active composition;

Figure 2 is another configuration of such a system.

Dictionary of terms used

In this summary of the invention making reference to some of the terms that may be consistent with (but may not comply with) the terms, which are publicly available dictionaries. To provide a more exact description of the invention presented here, the following terms, making the clarity and completeness of understanding. Note that although an attempt is made to give a precise and rigorous definition of all the terms, but naturally, not all values that are associated with these terms, will find its full definition. Accordingly, it is planned to bring the total value of each term, which follows from the common usage of this term in the context of the relevant prior art, or the values contained in the dictionary. If given the definition is in conflict with the definition that is used in the dictionary or in the relevant prior art, it is necessary to use in the context of this description of the invention, there is freedom of choice implied in the meaning of the term. You can advise them not to give used terms broader value is their in comparison with the what is used in the description, with the purpose of deep understanding of all the implied variations.

Optically active composition

When using this term in the present invention means that the composition is called "optically active", if the composition interacts with light. In this process, the mechanisms of both absorption and radiation.

Photoluminous

"Photoluminous" is a light-emitting compound, which can be optically initiated.

Light-emitting semiconductor

Light-emitting semiconductor is any solid-state semiconductor device that emits light by passing current through it. Light-emitting semiconductors include both LEDs and more complex structures, including laser diodes.

A detailed description of the preferred variants of the invention

According to each preferred implementation of the invention, there are described compositions and systems of the optically active compositions, and combinations of these compositions with a semiconductor InGaN structures. Assume that each of the preferred variants of the invention may include both the composition and the optical system. This also implies that the composition and optical the Kai system of one preferred embodiments of the invention may differ from the composition and the optical system of another preferred embodiments of the invention.

Crystals "antanaslietuva silicate" - Langasite belong to the class of piezoelectric materials with an average value of the coefficient of Electromechanical coupling (K=16%, for the case of optimal cutoff). This is the value of the Electromechanical coupling coefficient indicates a high temperature stability characteristics for these crystals, as well as about the absence of a phase transition when approaching the melting temperature. All this is of great interest to professionals working in areas of technology where required temperature stability. The main characteristics of the Langasite below in comparison with the characteristics of Quartz and Lithium Tantalate.

Table 1
PropertiesQuartzThe langasiteTantalate Lithium
The class of symmetry32323m
Melting point, deg. Celsius161014701650
Phase transition573,3 -660
The Electromechanical coupling coefficient K2EMC, %71644
The optimal cutting directionATYX
Temperature coefficient of frequency TFC, ×10-6/°C0,61,64

From prior art it is known that on the basis of material Langasite are exceptional optical and electronic devices, such as a frequency filter on surfactants. However, the system proposed in this invention, describes a Langasite from a slightly different point of view, demonstrating its properties as an optically active composition. In other words, Langasite crystals interact with photons, which is manifested in the optical absorption and spontaneous emission. Langasite crystals exhibit interesting properties in relation to the absorption and emission of photons. In particular, the electrons in the crystal lattice are easily transferred to an excited state by absorption of photons of the corresponding spectrum. Radiation with a wavelength in the interval for which f 0,1-0,45 micron excites the electrons, bound in the crystal lattice. In the recombination process, the crystal emits photons of lesser energy compared with the energy of the absorbed photon. When the wavelength of the emitted photon of longer wavelength of the absorbed photon. Due to such characteristics of Langasite crystals create an environment conducive to shift the wavelength of the primary radiation. Langasite crystals grown in an appropriate way to demonstrate the properties of the optically active compositions, such as phosphors or photoluminous that has a utilitarian value. As Langasite crystals are highly sensitive to the excitation of their ultraviolet and blue radiation, this indicates that the Langasite crystals can be easily excited by these wavelengths, and points to the fact that the Langasite is the ideal high-efficiency phosphor for use in LEDs.

Is currently undergoing active development in the industry, aimed at the creation of the led systems, emitting white light. There is a great need for the creation of led systems that can be used in the field of General lighting. One of the main approaches in this area is the use of led, which emits violet or blue light in combination with the phosphor, the cat is who provides the necessary shift of the wavelength. A necessary property of such phosphors is that they are excited by ultraviolet or blue radiation, which generates the semiconductor structure, and then these phosphors re-emit light with wavelengths lying in the green, yellow or red regions of the visible spectrum. The light that is emitted by the phosphor is mixed with the blue emission of the led and produces a wide range, which is perceived by the human eye as white light. Accordingly, the main part of this invention describes a combined light-emitting device, which is a combination of ultraviolet or blue led in combination with a phosphor based on Langasite.

In the manufacture of compositions based on Langasite for such optical systems there is considerable scope for manipulation of components of the connection in order to achieve the desired effects. In particular, in the synthesis of crystals it is possible to introduce different elements (actuators)that are embedded into the crystalline lattice properly. You can also affect the crystals by changing the geometric dimensions of the crystals, such as crystals can be ground and sifted through a sieve to obtain powder containing many small crystals of a given size. There are additional who sustained fashion possible impact on forming processes to produce the desired output properties of the phosphor, for example, the annealing process may be recommended to obtain a powder of the phosphor with certain desired characteristics.

A particularly interesting point that crystal Langasite can be doped by lanthanides, which serve as optical activators. Such elements include: Cerium, Scandium, Yttrium, Gadolinium, Ytterbium, Lutetium, Samarium, Europium, Terbium, Erbium, Dysprosium, Praseodymium, Golemi, Thulium, which are denoted as CE, Sc, Y, Gd, Yb, Lu, Sm, Eu, Tb, Er, Dy, Pr, and Tm.

Net connection Langasite is described by the formula La3Ga5SiO14. In the process of crystal formation can replace some of the atoms of Lanthanum atoms other lanthanides such as Cerium atoms. Typically, the amount of dopant is very small compared with the amount of lanthanum. For example, in the composition for every 100 or even 1000 atoms of Lanthanum can be only one atom of Cerium.

The introduction of dopants (activators) provides the variation of the optical properties of the material. Choosing alloying impurity and its concentration, can cause a shift of the optical sensitivity of the crystal. For example, the spectral peak of the excitation radiation can be shifted into the region of longer wavelengths or shorter wavelengths due to the various alloying elements. The wavelength emitted by the crystal light can be shifted in the poor end of the spectrum through the introduction of specific impurities in the crystal Langasite. It is also possible to influence the intensity of the emergent radiation and the efficiency of excitation through the introduction of various impurities. Each alloying impurity can have its own special effect. From experiments it was found that the introduction of the following impurities facilitated the registration of certain influence on the output optical properties of crystals. These results are shown below in Table 2.

Table 2
Rare earth elementsEquity ratio of atomsThe influence on the output parameters
Y0.01 to 0.3The increase in intensity, the shift of the spectral maximum
Gd0.01 to 0.3The increase in intensity, the shift of the spectral maximum
Sc0,001-0,1The increase in intensity, the shift of the spectral maximum
Lu0,001-0,1The increase in intensity, the shift of the spectral maximum
Yb0,001-0,1Change the time of the afterglow
Pr0,001-0,05The appearance of an additional peak A=615-640 nm
Sm0,001-0,1The change in luminescence intensity
Eu0,001-0,1The change in luminescence intensity
Tb0,001-0,1The change in luminescence intensity
Er0,001-0,05The change in luminescence intensity
Dy0,001-0,05The change in luminescence intensity
Ho0,001-0,05The change in luminescence intensity
Tm0,001-0,05The change in luminescence intensity
Yb0,001-0,05The change in luminescence intensity

In choosing the accordance with this invention the phosphor, activated by Cerium ion, is one example implementation of the invention. This variant of the phosphor may be represented by the stoichiometric formula La3-xCexGa5SiO14. This phosphor has a crystal structure of the Langasite related to structural group P321(D23), where the stoichiometric value of the index lies in the interval x=0.001 to about 0.15. Inorganic phosphors having such a formula, typically emit light with a peak in the region of λ=to 0.480-0,580 microns.

Upon excitation of such a phosphor emission from InGaN LEDs certain proportion of the light emitted by the led, interacts with the phosphor, causing it to emit light in the above wavelength. This radiation is mixed with the emitted light, which was not browseinterval with phosphor and has retained its original wavelength. Together, these two rays form a wide range, which is perceived as white light. In this combined light-emitting device can receive light with a color temperature from T=3000 K To T=12000 K.

There are no restrictions on the process of activation of Langasite crystals, they can be activated not only by Cerium, but also some other elements and combination of elements from the group of lanthanides. For example, you might doped Langasite the Praz what Dimon to obtain the emission spectrum with maxima in the region of λ=0,580-0,620 microns; Europium - λ=0,590-of 0.625 microns; Dysprosium - λ=0,570 microns; Terbium - λ=to 0.480-0,545 microns and Erbium - λ=0,530 microns.

Such possibilities in the choice of activator is allowed to have some freedom in the design of the led with respect to the wavelength of the exciting radiation. This point is especially important when using a phosphor in combination with led-based nitrides, for which it is possible to adjust the wavelength of the radiation. With such a good choice of parameters associated with the radiation wavelength, it is possible to achieve a very accurate match the efficiency of the phosphor and the selected emitter to obtain the required values of the color temperature.

The phosphor based on Langasite can be produced in accordance with known technology used for ceramics. For example, the oxides are mixed in the following amounts: La2O31,49 M; Ga2O32.5 M; SiO21 M and SEO20.02 M, in accordance with a given stoichiometric formula. These oxides are added to 0.05 M boric acid, which is used in this case as liquid-phase mineralizer. The mixed oxides is carried out in a special device (atricure, mill)using Zirconia balls as the crumbling of the elements. These crumbling elements with a ratio of mixture 1:10 the servant of the melt within 2 hours. Next, the mixture is placed in lundbye crucibles with a volume of 0.5 liter, which is installed in an electric furnace with controlled temperature and atmosphere of H2:N2=2:98. Heating of the crucible is carried out incrementally with time at T=500°C for 1 hour; 900°C for 1 hour; 1100°C for 1 hour and 1300°C for 2 hours. Then the contents of the crucible is cooled in the oven to 100°C. the compound Obtained is washed in hot acidified (pH=5) water, sifted through a sieve of 400 microns and dried at a temperature of 120°C for 2 hours.

When using Langasite as photoluminous it is produced in powder form. After synthesis of the phosphor in the form of crystallites then it can be crushed into fine powder by means of various processes of grinding and filtering. In this way it is possible to obtain a phosphor with a given dispersion, where the size of the crystals of the phosphor will have the dimensions necessary to achieve the best system performance.

During the experiments it was found that the phosphor should be prepared in the form of a polydisperse system, where the geometric dimensions of the grains of the phosphor exceed the peak wavelength of luminescence at 8-40 times. Preferred the smallest grain size of the phosphor is about d=4 μm, which, as will be shown, due to the absence of significant Svetova what about the scattering, reducing the overall efficiency of the system. The upper limit of the grain size of the phosphor is about d=20 μm and due to the possibility of obtaining nerastraivaisya phosphor suspension in the polymer, which is used for forming the translucent layer, well attached to the surface of a semiconductor crystal.

Since the main objective of the phosphor based on Langasite is getting broadband or "white" radiation when using this phosphor together with a blue or ultraviolet led, it is important to mention the possible ways of phosphor on the led chips. For good interaction between the photons, which are emitted by a semiconductor chip, that should get activated on Langasite crystals. Some common approaches to the process of the phosphor suspension of phosphor may cover the semiconductor chip. The radiation emerging from the semiconductor chip passes through the suspension and interacts with Langasite crystals. The first preferred embodiment of the present invention shown in figure 1, where, in particular, the led package is formed by attaching a lens 2 to the substrate 1. Semiconductor chip, for example an InGaN diode 3, is mounted on a substrate. Next, the semiconductor chip is covered with a phosphor suspension, to ora generates a specific configuration of the coating layer 4, in which the phosphor. The chip is electrically connected by means of wires 5. In some embodiments, execution of the phosphor is mixed with a relatively transparent binder material is applied directly on the semiconductor chip, as is usually done in the prior art.

In modern packaging options LEDs used colloidal suspension of phosphor in any binder material. As a binder material can be used the polymer added and stirred Langasite crystals. A polymeric material having a sufficient density and viscosity, promotes the retention of Langasite crystals in suspension. This fact makes it easy to put a gel-like suspension of the phosphor Langasite polymeric material into the cavity, which can accommodate led chips.

Preferred polymers belong to the group of polyethylsiloxane or polyepoxide compounds having a molecular weight from M=2000 M=20000 carbon units. Such polymers have a high viscosity and flow as required, ensuring the formation of the layer containing grains of phosphor dispersed in the polymer. The preferred minimum number of grains of the phosphor in the polymer is from 10% in mass units, while the maximum value is about 75%. Rudnaya optimal value of the amount of phosphor in the slurry ranges from 45% to 65%. Such concentrations is possible to form uniform layers of thickness from 20 to 100 microns, well fixed on the surface of the led chip and covering the entire emitting surface of the led chip, including its side faces.

Figure 2 shows another preferred embodiment of the light-emitting kombinirovanno peripherals, in which the colloid system based polymer gel has a specific configuration and contains crystals of a phosphor based on Langasite. The substrate 21 when the connection with the lens 22 forms the package. The semiconductor chip 23 is attached to the substrate within the cavity of the lens element. All cavities can be filled with a viscous gel 24. By wire 25 is formed electrical circuit with a semiconductor chip.

As noted in the above section, associated with the description of the prior art, standard and well-known system of white led typically consists of InGaN diode with a YAG phosphor. It is useful to draw a comparison between the Phosphor Langasite and YAG phosphor for a more complete understanding of the physical differences between the two types of songs.

Table 3 below shows the comparison of such parameters as: symmetry, lattice parameters, structure, molecular weight, density, th is the first extension, thermal conductivity, melting point, refractive index, etc. of the table shows that these materials are significantly different. Each composition has its own distinctive physical characteristics that can be used to advantage in various optical systems.

Table 3
PropertiesY3Al5O12BeholdLa3Ga5SiO14Behold
SymmetryIa3dP321(D23)
The lattice parametersa=1,205a=0,810
StructureCubicTrigonal
Molecular weight593,611017,32
Density, g/cm3the 4.65-5,0of 5.75
Thermal expansion, 1-6the hail.8,23,1-5,1
Talopram the bullying; appropriate, Watt/cm deg0,130,35
The melting temperature, T°C19501480
Refractive index1,85-1,951,92
The concentration of the activator, % of CE atoms1,010
The spectral region of transparency, microns0,24-60,35-4,0
The position of the maximum of the luminescence spectrum, λmaxnm540-580480-600

From table 3 it can be seen that instead of the cubic structure, which is associated with garnet phosphor, the phosphor of the Langasite has a trigonal structure with two lattice parameters. The bond length of the lattice is similar in size and depend on the atoms of the lanthanides. Due to the nature of the crystal and of Cerium atoms (one of the lanthanides) there is very good interaction. The brightness of the phosphor, the easier it is managed, the less the Cerium is in substantial quantities in the crystal structure.

High concentration of Cerium ions contributes to the value of kvantovoj the output (quantum efficiency) of the luminescence of the phosphor, which can reach up to η=90-92% for Langasite, while the best value for the YAG phosphor is η=82-88%. At the same time, slightly smaller refractive index Langasite provides a great angle of the radiation output of the grains of the phosphor, which is determined according to the formula φ=arctan(n2/n1), where n1and n2the refractive indices of the grains of the phosphor and a binder polymer, respectively.

If the reflection coefficient of the layer garnet phosphor at λ=470 nm is equal to R=18-25%, phosphor Langasite this value is equal to R=12-18%. The decrease of the reflection coefficient can reduce the value of optical scattering in polymerchemistry layers. At the same time, this allows you to create greater uniformity in the layer, which in turn contributes to the persistence and stability of the color coordinates of the emitted white light.

Thermal stress associated with garnet phosphor, are not observed in the phosphors based on Langasite and, therefore, such phosphors work better at high temperatures. This fact is due to the smaller value of the coefficient of thermal expansion of the grains of Langasite. The high conductivity of these materials also contributes to the effect of a small value of thermal stresses in polymer layers or organic binder is m the material.

Interesting benefits that arise from consideration of the characteristics of some examples of the optically active compositions based on Langasite. Table 4 shows 15 examples of luminophoric compositions. For each composition specified luminous intensity of the output radiation (Candela, cd). Also presents color coordinates describing the observed color characteristics. Additionally, Table 4 shows the amount equal to the value of the half angle of emission θ.

Table 4
NoThe phosphor compositionLuminous intensity (cd)Color coordinatesColor
1La2,99CE0,01Ga5SiO142,00,29 0,30Blue-white15
2La2,89Ya 0.1Ce0,01Ga5SiO142,20,31 0,33Solar-white16
32,30,32 0,32White16
4La2,98Lu0.01Ce0,01Ga5SiO142,050,34 0,33White15
5La2,298CE0,01Yb0,01Ga5SiO142,020,32 0,36White-yellow16
6La2,298CE0,01Yb0,01Ga5SiO142,30,36 0,38White-yellow16
7La2,998CE0,01Sm0,001Eu0,001Ga5SiO142,000,32 0,33White15
8La2,998CE0,01Er0,001Ho0,001Ga5SiO142,00 0,32 0,34White15
9La2,989Y0,09CEof 0.2Tb0,001Ga5SiO142,80,38 0,40Warm white18
10La2,999CE0,001Ga4Ina 0.1O142,00,33 0,33White16
11La2,99CE0,01Ga4In1,0O142,750,39 0,42Warm white16
12La2,99CE0,01Ga4,999In0,001Si0,99Ge0,01O142,40,36 0,40Warm white16
13La2,99CE0,01Ga4,7Infor 0.3Sifor 0.9Gea 0.1O142,20,38 0,38Warm white 15
14La2,99CE0,01Ga4,7Infor 0.3Si0,7Gefor 0.3O142,40,38 0,36Warm white15
15Y3Al5O12:Ce1,8-2,20,31 0,32Solar-white12

The examples above are directed to specific embodiments, which illustrate the preferred options of the devices and methods described in this invention.

From the above description it is clear how highly effective, inexpensive, optically active composition can be used in combination with optical systems to ensure the shift of the emission wavelength.

Although for illustrative purposes have been disclosed preferred implementations of the present invention, the experts in this field should understand that there are a variety of modifications, additions and substitutions that are not beyond the scope and essence of the present invention, as disclosed in the accompanying claims.

1. Light-emitting combined device, characterized in that it contains svatos Wausau semiconductor structure and photoluminous based on Langasite, where the light-emitting semiconductor structure is located in relation to photoluminous the Langasite so that some amount of light emitted from the semiconductor structure, interacts with photoluminous and by re-emission phosphor changes the wavelength.

2. The device according to claim 1, characterized in that the light-emitting semiconductor structure is led structure of InGaN.

3. The device according to claim 1, characterized in that photoluminous produced by activation of Langasite Cerium.

4. Optically active composition, characterized in that it has the formula:
La3-x[Me1]5[Me2]1O14:[At]x,
where Me is at least one of the two metals of group III: Ga and In;
Me2is at least one of the two elements, group IV: Si and Ge;
Atxis at least one lanthanide from the group: CE, Sc, Y, Gd, Yb, Lu, Sm, Eu, Tb, Er, Dy, Pr, and Tm,

where 1≤N≤14 and x≤3.

5. Optically active composition according to claim 4, characterized in that it has a crystalline structure characterized by:
P321(D23).

6. Optically active composition according to claim 4, characterized in that Me1is a combination of two metals Ga, and In.

7. Optically active composition according to claim 4, characterized in, th is Me 2is a combination of two metals, Si and Ge.

8. Optically active composition according to claim 4, characterized in that the composition consists of crystals, where the average size of the crystals has a value of from 8 to 40 times greater compared to the wavelength maximum of the emission spectrum.

9. Optically active composition, characterized in that it has the formula:
La3-x[Ln]xGa5SiO14,
where 0≤x≤0.3, and a [Ln] - lanthanid.

10. The device according to claim 2, characterized in that the phosphor made in accordance with the formula:
La3-x[Me1]5[Me2]1O14:[At]x,
where Me1is at least one of the two metals of group III:Ga and In;
Me2is at least one of the two elements, group IV: Si and Ge;
Atxis at least one lanthanide from the group: CE, Sc, Y, Gd, Yb, Lu, Sm, Eu, Tb, Er, Dy, Pr, and Tm,

where 1≤N≤14 and x≤3.

11. The device according to claim 1, characterized in that the semiconductor light-emitting structure is covered with colloidal phosphor-polymer suspension.

12. The device according to claim 11, characterized in that the polymeric material are polyethylsiloxane or polyepoxide compounds having a molecular weight from 2000 to 20,000 carbon credits.

13. The device according to claim 11, characterized in that the mass ratio of the phosphor and the polymer is a component lie in the region from 0.1 to 0.75.

14. The device according to item 13, wherein the thickness of the phosphor-polymer layer is from 20 to 100 microns.

15. Light-emitting combined device, wherein the semiconductor diode is partially covered with the phosphor Langasite, activated lanthanide.

16. The device according to item 15, wherein the semiconductor diode is InGaN structure.

17. The device according to item 15, wherein the phosphor made in accordance with the formula:
La3-x[Me1]5[Me2]1O14:[At]x,
where Me1is at least one of the two metals of group III: Ga and In;
Me2is at least one of the two elements, group IV: Si and Ge;
Atxis at least one lanthanide from the group: CE, Sc, Y, Gd, Yb, Lu, Sm, Eu, Tb, Er, Dy, Pr, and Tm,

where 1≤N≤14 and x≤3.

18. The device according to item 15, wherein the partial coating of a semiconductor diode is a colloidal system containing dispersed crystals of the phosphor Langasite.

19. The device according to p, characterized in that the colloidal system contains a polymeric binder material.



 

Same patents:

Illumination device // 2425432

FIELD: physics.

SUBSTANCE: illumination device 101 contains the following: a light source 102; a solid-state wavelength converter 106 for converting light emitted by the light source to another wavelength; an optical component 110 with a reflecting surface 111 for redirecting light emitted by the converter 106 in the required direction (A) for output from the device, in which the converter 106 is mechanically supported by the said optical component 110, in order to form a separate structure which is mechanically connected to the optical component.

EFFECT: invention enables to design a stronger illumination device which is relatively easy to make, and which can emit in a wide spectrum especially in the white emission spectrum.

12 cl, 2 dwg

FIELD: physics.

SUBSTANCE: described light-emitting diode (LED) contains a crystal (crystals), a conical reflector and luminophor, wherein the crystal emits in the violet spectral range, the luminophor is base on barium-strontium orthosilicate, the reflector has an optimum angle of inclination of walls and height, a polymer layer with the luminophor is deposited on the reflector, as well as on the light-emitting surface of the LED.

EFFECT: highly efficient green LED, with luminous efficacy which is higher than that of traditional green LEDs, is obtained based on the disclosed invention.

6 cl, 1 dwg

FIELD: physics.

SUBSTANCE: light-emitting device has a light-emitting element, a red luminophor formed from a nitride luminophor, and a green luminophor formed from a halogen-silicate, in whose radiation spectrum of which there is a first peak at wavelength between 440 nm and 470 nm, a second peak at wavelength between 510 nm and 550 nm and a third peak at wavelength between 630 nm and 670 nm. The minimum relative intensity of optical radiation between the second peak wavelength and the third peak wavelength is equal to or less than 80% of the least relative intensity of optical radiation at the second and third peak wavelengths.

EFFECT: light-emitting device has high quality of colour reproduction.

7 cl, 8 ex, 11 dwg

FIELD: physics.

SUBSTANCE: light-emitting device has a light-emitting element, a red luminophor formed from a nitride luminophor which emits light when excited by light emitted by the light-emitting element, a green luminophor formed from a halogen-silicate, which emits light when excited by light emitted by the light-emitting element, and an yttrium aluminium garnet (YAG) luminophor which emits light when excited by light emitted by the light-emitting element.

EFFECT: light-emitting device has high quality of colour reproduction.

7 cl, 11 ex, 14 dwg

FIELD: physics.

SUBSTANCE: illumination device (1) comprises, for example, diodes LED (L1, L2, L3, L4) with separate emission spectra. Detectors D1, D2, D3, D4) can generate a vector of measurement signals (S1, S2, S3, S4) which represent light output of one active light emitter. Further, based on a linear relationship obtained during the calibration procedure, the characteristic value of the light output of that light emitter (L1, L2, L3, L4) is calculated using the measurement vector, wherein said characteristic value is based on the decomposition coefficient of an individual emission spectrum on basic functions.

EFFECT: improved method.

25 cl, 6 dwg

FIELD: physics.

SUBSTANCE: light-emitting system (1), comprising a radiation source (2), capable of emitting first light with at least a first wavelength spectrum, first fluorescent material (4), capable of absorbing at least partially the first light and emit second light with a second wavelength spectrum, second fluorescent material (8) capable of absorbing at least partially the first light and emit third light with a third wavelength spectrum, in which the first (4) or the second (8) fluorescent material is a polycrystalline ceramic with density higher than 97% of the density of monocrystalline material, and the corresponding other fluorescent material is a powdered luminophor with average particle size 100 nm <d50%<50 mcm.

EFFECT: invention enables to design an illumination system which emits white light with high colour rendering index, high efficiency, clearly defined colour temperature and good illumination quality, with correlated colour temperature, and enables regulation of the correlated colour temperature of the illumination system.

16 cl, 8 dwg

FIELD: physics.

SUBSTANCE: light-emitting diode lamp has an aluminium radiating housing with a power supply unit in its top part, formed by a hollow rotation body with external radial-longitudinal arms which form the outline of the lamp, fitted with internal radial-longitudinal arms with windows between them and a circular area on the butt-end of the external radial-longitudinal arms in its inner part, on which light-emitting diodes are tightly mounted. The design of the radiating housing with windows between the internal radial-longitudinal arms and guides in the top and bottom parts of the radiating housing, provides efficient convectional heat removal from powerful light-emitting diodes separated from each other by inner and outer streams. The light-emitting diode module has a light-emitting diode fitted into an optical lens and tightly joined to a printed circuit board through a flexible sealing element encircling the light-emitting diode, and the light-emitting diode is rigidly joined to a heat-removing copper plate through a hole in the printed circuit board.

EFFECT: stable light output and colour temperature over the entire service life, high light flux is ensured by a set of structural solutions of the radiating housing and compact light-emitting diode modules.

5 cl, 5 dwg

FIELD: physics.

SUBSTANCE: proposed nano radiator comprises 4-6 nm-dia nucleus of noble metal surrounded by two concentric envelopments. Envelopment nearest to nucleus represents an optically neutral organic layer with thickness of about 1 nm. Second 1-3 nm-thick envelopment is made up of J-aggregates of cyanine dyes. During electron excitation of metal nucleus plasmons, the latter actively interact with J-aggregate envelopment to excite cyanine dyes (Frenkel's excitons) and radiate light in visible range. Metal nucleus electrons may be excited by both photons and electrons.

EFFECT: high quantum output of luminescence and controlled spectrum of radiation in visible range.

3 cl, 1 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: described light-emitting diode has an emitting crystal (crystals), a conical holder and a luminophor, where the holder is made from white material with angle of inclination to the wall equal to 60+5-10 degrees and height equal to 2-3 times the cross dimensions of the crystal. The walls of the holder are covered by a layer of a transparent polymer in which luminophor is distributed. The cavity of the holder is completely filled with a transparent polymer with a flat (or almost flat) surface covered by a layer of polymer in which luminophor is distributed. The invention enables design of light-emitting diodes which emit white light with luminous efficacy of up to 120 lm/W.

EFFECT: high luminous efficacy.

5 cl, 1 dwg, 1 tbl

FIELD: electricity.

SUBSTANCE: manufacturing method of semiconductor item having composite semiconductor multi-layer film formed on semiconductor substrate, according to invention, involves the following: preparation of element including layer (1010) removed by etching, composite semiconductor multi-layer film (1020), insulating film (2010) and semiconductor substrate (2000) on composite semiconductor substrate (1000), and having the first groove (2005) which passes through semiconductor substrate and insulating film, and groove (1025) in semiconductor substrate, which is the second groove provided in composite semiconductor multi-layer film so that it is connected to the first groove, and etching agent contacts the layer removed by etching as to the first groove and the second groove, and thus, removed layer is etched to separate composite semiconductor substrate from the above element.

EFFECT: increasing yield ratio and simplifying manufacturing procedure.

28 cl, 15 dwg

FIELD: chemistry.

SUBSTANCE: disclosed is a luminescent composition for marking roads, which contains an aluminate type luminescent (phosphorescing) pigment and polymer binder selected from a group comprising: epoxy, urethane, acrylate, alkyd and composite polymer resins. The luminescent pigment is pre-treated in order to protect it from moisture using solutions of reagents selected from a group comprising mono-substituted phosphates, H2SO4, H3PO4, a mixture of tri- or disubstituted phosphates and at least one acid: HCl, H3SO4 or HNO3. Disclosed also is a luminescent paint for making roads, which contains an aluminate type luminescent (phosphorescing) pigment or a luminescent composition and a water or non-water based road paint or enamel. In another version, the luminescent paint is obtained by mixing a pigment which first protected from hydrolysis, polymer binder and a water or non-water based road paint or enamel: - luminescent pigment 2-60; polymer binder 4-20; road paint or enamel 94-20.

EFFECT: invention provides reliable protection of the pigment from hydrolysis, enables regulation of the amount of polymer binder which affects colour characteristics and technological aspects, as well as the size of particles of the luminescent pigment, which is important when mixing the pigment with components of compositions or paints.

4 cl, 8 tbl, 58 ex

FIELD: chemistry.

SUBSTANCE: disclosed is a colourless phosphorescing luminophor, which is a coordination compound of terbium (III) with [2-(aminocarbonyl)phenoxy]acetic acid (HL2) and having formula Tb(L2)3, and specifically: , having high quantum efficiency of luminescence, considerable luminescence intensity and fluorescence maxima at 20500, 18300, 17000, 16000 cm-1.

EFFECT: possibility of use in protecting bond payer and documents from forgery, and as radiating substances in electroluminescent devices.

1 dwg, 1 ex

FIELD: physics.

SUBSTANCE: described is light-converting material containing a matrix and at least one composite which converts UV radiation to radiation of a different colour, with particle size from 10 nm to 1000 nm, selected from a group ZnO:Zn and rare-earth element compounds of formula: MexaAybRzc , where Me denotes a metal, selected from a group comprising yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, aluminium, bismuth, manganese, calcium, strontium, barium, zinc or mixture thereof; A denotes a metal selected from a group comprising cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, holmium, erbium, terbium, ytterbium, titanium, manganese; R is an element selected from a group comprising oxygen, sulphur, boron, titanium, aluminium and/or compounds thereof with each other; a, b and c denote the charge on the Me ion, A or R, respectively, x≥1, 1.0 ≥ y ≥ 0.0001, z is defined by ax + by = cz. The invention also describes a composition for producing said material, containing the following in wt %: said composite - 0.001-10.0; matrix-forming component - the rest.

EFFECT: invention increases intensity of converting UV radiation to infrared radiation, blue to green spectrum region, and therefore increases plant yield.

27 cl, 25 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in production of inorganic yttrium oxysulphide-based multifunctional anti-Stokes luminophors which can be used for converting infrared radiation to visible luminescence, for protecting bond paper and documents, strict accounting forms, conformity marks of goods and articles, excise and identification marks, banknotes, as well as for making emergency and signal light systems, evacuation, fire, warning and indicator light marks, for pointers in shafts, tunnels, overpasses, metro and passages for information-direction boards in motorways and decorative cosmetics. The yttrium oxysulphide-based luminophor is activated by titanium ions and coactivated by magnesium ions, and also contains a cationic sublattice of trivalent ytterbium and erbium ions and has a chemical composition corresponding to the following empirical formula: (Y1-X-YYbxEry)202S:Ti0.12,Mg0.04, where 0.01<X<0.05; 0.01<Y<0.05.

EFFECT: more intense visible anti-Stokes luminescence during excitation of infrared radiation in the 0,90-0,98 mcm range.

7 cl, 1 tbl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention describes a method of modifying anti-Stokes luminophors based on oxychlorides of rare-earth elements, involving treatment of a luminophor with low-melting glass with flow temperature of 560-600°C in amount of 7-20% of the weight of the initial luminophor at 560-600°C for 0.5-1 hour.

EFFECT: obtaining modified anti-Stokes luminophor with high output and high moisture resistance with retention of high level of luminous intensity during infrared excitation.

9 ex

FIELD: physics, optics.

SUBSTANCE: invention relates to photoluminophors designed for converting emission of blue light-emitting diodes to the yellow-red region of the spectrum in order to obtain resultant white light, particularly to a cerium doped luminophor based on yttrium aluminium garnet used in two-component light-emitting diode light sources. The invention describes a luminophor for light sources which contain aluminium, yttrium, cerium, lutetium and oxygen in the following ratio: (Y1-xCex)3Al5O12 and 5-60 wt % over 100% (Lu1-yCey)2O3, where x=0.005-0.1; y=0.01-0.1. The invention provides a fine-grained luminophor with luminescent emission band maximum at λ≈590 nm, while lowering temperature and duration of synthesis.

EFFECT: use of such a luminophor in a two-component light source with a blue light-emitting diode enables to obtain resultant "warm" white light with high colour rendering index, increases uniformity of light scattering and reduces energy consumption during synthesis.

1 cl, 1 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: invention is meant for the chemical industry and can be used to protect bond paper and valuable documents, strict accounting forms, conformity marks of articles, excise and certification marks. An infrared luminophor having formula Y2-x-yErxCeyO2S, where x=0.20-0.45; 1·10-4≤y≤5·10-3 is described.

EFFECT: obtaining an infrared luminophor based on yttrium oxysulphide activated by erbium ions and co-activated by cerium ions, which has minimal visible anti-stokes luminescence when excited with laser radiation in the 0,90-0,98 mcm range and high intensity of stokes infrared luminescence in the 1,5-1,5 mcm range.

1 cl, 1 tbl, 12 ex

FIELD: printing industry.

SUBSTANCE: valuable document has marking, which contains luminescent compound that has both anti-stokes and Stocks law luminescence, with composition of Ln 1-X-Y-Z YbX ErY CeZ MeIC MeVID PI-D O4+D/2-C where: MeI - Li or Na, MeVI - W or Mo, Ln - Y, La, Gd, 0.1 ≤ x ≤ 0.9; 0.005 ≤ y ≤ 0.2; 0.0001 ≤ z ≤ 0.01; 0.001 ≤ c ≤ 0.1; 0.001 ≤ d ≤ 0.1; or compound of the following composition: Ln 2-X-Y-Z YbX ErY CeZ O2 S, where Ln - Y, La, Gd, 0 <x ≤ 0.2; 0.1 ≤ y ≤ 0.4; 0.0001 ≤ z ≤ 0.005; or compound of the following composition: Ln 2-X-Y-Z ErY CeZ O2 S; where Ln - Y, La, Gd, 0 < x ≤ 0.2; 0.1 ≤ y ≤ 0.4; 0.0001 ≤ z ≤ 0.005. Marking may be made by printing method, for instance offset method of printing. Method for identification of valuable document authenticity with all above mentioned criteria inherent in it includes detection of hidden protective marking on a valuable document by measurement and further analysis of dependency extent of stokes and anti-stokes luminescence strip intensity on density of excitation radiation capacity.

EFFECT: improved level of valuable document protection.

6 cl

FIELD: chemistry.

SUBSTANCE: invention relates to liquid crystal materials and can be used as flawless luminescent optical media in electro-optical and magneto-optical devices. A lyotropic liquid crystal composition is described, which contains oxyethylated surface active substance in form of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis[29-hydroxy(3,6,9,12,15,18,21,24,27-oxanonacosaneoxy]-pentacyclo[19.3.-1.13,7.19,13.115,19]octacosa-1(25)3,5,7(28)9,11,13(27)15,17,19(26)21,13-dodecane, hexahydrate of europium nitrate and solvent in form of ethanol. Components of the composition are in the following ratio, wt %: said oxyethylated surface active substance - 55 to 79, hexahydrate of europium nitrate - 12 to 35, ethanol - 5 to 33.

EFFECT: production of lyotropic liquid crystal composition, with twelve times more luminescence efficiency and double the mean life of luminescent glow.

1 cl, 5 dwg, 1 tbl, 4 ex

FIELD: materials useful in agriculture, medicine, biotechnology, light industry.

SUBSTANCE: claimed material includes matrix and at least one light-converting compound, namely luminophor converting UV radiation into radiation of other colors and has particle size from 0.3 to 0.8 mum and general formula of MexaAybRzc, wherein Me is yttrium, lanthanum, cerium, praseodium, europium, gadolinium, dysprosium, erbium, ytterbium, aluminum, bismuth, manganese, calcium, strontium, barium, zinc, cesium; A is cerium, praseodium, europium, gadolinium, dysprosium, erbium, ytterbium, aluminum, indium and/or combination thereof; R is oxygen, sulfur, phosphorus, boron, vanadium, titanium, aluminum, indium and/or combination thereof; a, b and c represent charge of Me, A or R ions, respectively; x >=1; 1.0>=y>=0.0001; z corresponds ax+by=cz. Aldo disclosed is composition for material production containing abovementioned light-converting compound in amount of 0.001-10.0; and balance - matrix-forming component, e.g. polymer, fiber, varnish- or adhesive-forming agent.

EFFECT: conversion of UV irradiation of increased effectiveness; increased plant productivity.

16 cl, 21 ex

FIELD: materials useful in agriculture, medicine, biotechnology, light industry.

SUBSTANCE: claimed material includes matrix and at least one light-converting compound, namely luminophor converting UV radiation into radiation of other colors and has particle size from 0.3 to 0.8 mum and general formula of MexaAybRzc, wherein Me is yttrium, lanthanum, cerium, praseodium, europium, gadolinium, dysprosium, erbium, ytterbium, aluminum, bismuth, manganese, calcium, strontium, barium, zinc, cesium; A is cerium, praseodium, europium, gadolinium, dysprosium, erbium, ytterbium, aluminum, indium and/or combination thereof; R is oxygen, sulfur, phosphorus, boron, vanadium, titanium, aluminum, indium and/or combination thereof; a, b and c represent charge of Me, A or R ions, respectively; x >=1; 1.0>=y>=0.0001; z corresponds ax+by=cz. Aldo disclosed is composition for material production containing abovementioned light-converting compound in amount of 0.001-10.0; and balance - matrix-forming component, e.g. polymer, fiber, varnish- or adhesive-forming agent.

EFFECT: conversion of UV irradiation of increased effectiveness; increased plant productivity.

16 cl, 21 ex

Up!