RU2313157C1 - Method for producing visible light and luminescent sources using this method (alternatives) - Google Patents

Abstract

FIELD: lighting engineering.

SUBSTANCE: proposed method for converting infrared radiation into visible light ranging between yellow-green and yellow to orange-yellow light at output optical power up to 10 W and efficiency of up to 20% includes irradiation of anti-Stokes phosphor in spectral range of 940 to 1030 nm, inorganic material whose spectral absorption band approaches that of infrared radiation being used as anti-Stokes phosphor. Two design alternates of visible light luminescent source are also proposed basing on this method which have different infrared light sources and respective phosphor.

EFFECT: enlarged chromatic range of produced light, enhanced optical power and efficiency.

21 cl, 8 dwg, 21 ex

Description

The invention relates to the field of lighting, namely, devices designed to emit light in the visible range, and can be used both in display devices and lighting.

Light sources exist in a wide variety of forms and sizes. In this case, for example, incandescent lamps are known as light sources, in which, as a rule, a tungsten wire is heated to the highest possible temperature by means of Joule heat. This creates thermal radiation. Light output of hot wires increases sharply with increasing temperature. In addition, so-called non-thermal radiation sources are also known, such as discharge lamps in the form of gas, mercury, sodium or metal halide discharge lamps in a high or low pressure design. (RU No. 2260226 MPK7 N01K 1/4, publ. 2003.11.10).

The disadvantage of all known types of light sources that are still working on electricity is that they are very inefficient in converting electrical power into visible light. The largest share of consumed electric power is the uneconomical power of losses in the form of predominantly heat.

Currently, inorganic light emitting diodes are most widely used in this field of technology, characterized, inter alia, by a long service life, a small footprint, insensitive to shaking and radiation in a narrow band of the spectrum. However, using the inherent radiation of a semiconductor material in LEDs, it is very inefficient to realize multiple radiation colors in a wide radiation range. Therefore, the brightest LED light sources with a wide white color of luminescence contain a converting phosphor that re-emits a narrow short-wavelength emission band of the LED into a wider long-wavelength spectrum from 500 nm to 650 nm.

There is a method of creating white light in which an LED emitting in the ultraviolet (UV) or blue region of the spectrum from 420 to 470 nm is combined with a mixture of phosphors consisting of at least two phosphors emitting with different spectra. The applied phosphor mixture always contains one red component and one green component. In this case, due to the mixing of these colors with blue radiation, white light arises. A luminescent light source based on it contains an LED emitting exclusively blue light, or a laser diode that interacts with a mixture of phosphors (WO 0033390, IPC S09K 11/07, published 2006.06.08).

However, an LED emitting exclusively blue light is made on the basis of AlGaN solid solutions and currently has insufficient radiation power (less than 300 milliwatts) due to the low conductivity of the p-type region. The heat loss arising during the passage of current through it causes the LED to warm up to 200 ° C, its low efficiency (less than 5%) and low brightness (not more than 40 lumens / watt).

The most sensitive to the human eye for illumination and display purposes in the visible range of radiation is green light. Until now, green LEDs have been produced based on the epitaxial structures of gallium phosphide solid solutions without a converting phosphor (Semiconductor Physics, Quantum electronics and optoelectronics, 2003, v.6, No. 4, p. 499-504).

However, the brightest green LEDs have an optical power of less than 200 milliwatts.

A known method of creating white light and a luminescent source based on it with a UV light emitting semiconductor element (WO 0033389, IPC H01L 33/00, publ. 2006.06.08), in which Ba ₂ SiO _{4 is} used as a phosphor for converting radiation into the visible region of the spectrum. : Eu ²⁺ .

However, the maximum emission of the phosphor Ba ₂ SiO ₄ : Eu ²⁺ is approximately 505 nm, so using this combination it is impossible to reliably create a radiation source in the visible range.

The closest way to create white light, adopted as a prototype, is a method that involves irradiating an anti-Stokes phosphor with infrared radiation, the phosphor being selected from the group of yttrium oxosulfides activated by trivalent erbium and ytterbium, and titanium-sapphire laser radiation is selected as the infrared source (excitation at 921 nm) (A.N. Georgobiani et al. "Infrared luminescence of compounds Y ₂ O ₂ S: Er ³⁺ and Y ₂ O ₃ : Er ³⁺ ", journal "Inorganic materials", 40 (2004), p. 963- 968).

However, the conversion efficiency was about 2%.

Known adopted for the prototype luminescent source of visible light containing an LED and at least one Stokes phosphor. Moreover, the LED emits blue and / or ultraviolet radiation, and the phosphor is an alkali-earth metal orthosilicate activated by divalent europium, the radiation of which is emitted in the yellow-green, yellow, or orange spectral region (RU, 2251761, IPC Н01L, publ. 2005.05.10).

However, the use of an LED to emit blue and / or ultraviolet radiation does not allow an optical power of more than 300 milliwatts to be obtained, which is necessary for lighting and display purposes.

The present invention solves the problem of converting infrared radiation into the visible range with a large output optical power and high efficiency.

The technical result in this case is the development of a method and devices based on it for producing light in the range from yellow-green, yellow to orange-yellow with an optical power of up to 10 watts and an efficiency of up to 20%.

The problem is achieved by developing a method for producing visible light, which includes irradiating an anti-Stokes phosphor with infrared radiation, the novelty of which is that irradiation is carried out by radiation in the spectral range 940-1030 nm, and inorganic material with a spectral absorption band close to that is taken as an anti-Stokes phosphor to the infrared spectral band.

In this application, the term "anti-Stokes phosphor" refers to a phosphor that converts long-wave infrared radiation into shorter wavelength visible radiation.

As inorganic material, you can take yttrium oxosulfide activated by trivalent erbium and ytterbium from one of the following compositions or a mixture of these compounds:

but)

Where

0.01 <x <0.05; 0.005 <y <0.05; x≥y; x + y <0.1

0.5 <a <1.5;

b)

Where

0.01 <x <0.05; 0.01 <y <0.05; x <y; x + y <0.1

0.5 <a <1.5;

As inorganic material, you can also take activated trivalent erbium and ytterbium yttrium oxide of one of the following compositions or a mixture of these compounds:

a)

Where

0.01 <x <0.05; 0.005 <y <0.05; x≥y; x + y <0.1

b)

Where

0.01 <x <0.05; 0.01 <y <0.05; x <y; x + y <0.1

In this case, erbium ions, smaller than yttrium ions, contribute to the shift of the radiation maximum to the shorter wavelength region, while larger ytterbium ions are centers of absorption of the infrared radiation of the LED. In addition, it was found that for crystallinity, emissivity, and especially for the stability of the phosphors according to this invention, an additional deviation in sulfur or oxygen from the stoichiometric composition is preferable.

In addition, when implementing the method, at least one additional phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese or alkaline earth magnesium disilicate: Eu ²⁺ Mn ²⁺ can be used: , with the formula (V)

Where

0.005 <x <0.5; 0.005 <y <0.5

and Me = Ba, and / or Sr, and / or Ca,

or from the group of ternary compounds doped with europium and bismuth, with the formula (VI)

where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si).

In this way, you can precisely set the white hue required for the respective application, and, in particular, you can get Ra (an indicator of the proximity of the color coordinate to white) more than 60.

The optimal result is obtained by irradiating the above-described phosphors with radiation in the spectral range of 960 nm.

Another aspect of the invention is a luminescent source of visible light based on the proposed method, containing an incandescent lamp. The novelty of the proposed source lies in the fact that it additionally contains an anti-Stokes phosphor containing at least one inorganic material with a spectral absorption band close to the IR spectral band, and the spectral range of an incandescent lamp includes a range of 940-1030 nm.

As the phosphor, at least one of the compounds of the formula (I), (II), (III) or (IV) is taken.

The phosphor can be mixed in the glass of a glass bulb of an incandescent lamp or deposited on the outer or inner part of a glass bulb of an incandescent lamp.

To increase the luminous flux emitted by the lamp, a reflective reflector layer can be applied to the lower part of the glass bulb of the incandescent lamp, and then the phosphor can be applied to the reflector and / or dispersed on the top of the glass bulb of the lamp placed above the reflector

An incandescent lamp may contain an additional phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese, or alkaline earth magnesium disilicate: Eu ²⁺ , Mn ²⁺ , with the formula (V)

Where

0.005 <x <0.5; 0.005 <y <0.5

and Me = Ba, and / or Sr, and / or Ca,

or from the group of ternary compounds doped with europium and bismuth, with the formula (VI)

where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si),

moreover, the additional phosphor is spatially located in the same region as the main, or placed relative to the main one after another in the direction of light propagation.

Another aspect of the invention is a luminescent source of visible light based on the proposed method, containing an LED and at least one phosphor, in which it is new that an LED containing a gallium arsenide LED chip is used as an LED, and a phosphor is taken anti-Stokes phosphor containing at least one inorganic material with a spectral absorption band close to the infrared spectral band.

It is known (V. P. Gapontsev, V. P. Minaev, V. I. Savin, I. E. Samartsev. “Medical devices based on high-power semiconductor lasers.” Quantum Electronics, 2002, No. 11, p. 1003-1006) that of the entire variety of electroluminescent diodes, the most efficient and bright luminescence are the LEDs of the IR range based on epitaxial structures from gallium arsenide. This is explained by the developed and simpler technology for producing doped layers with high electronic and hole conductivity from this material, in comparison with wider-gap semiconductors of the green (gallium phosphide) and blue (gallium nitride) spectral ranges. The most efficient and powerful LED to date is made specifically on the basis of gallium arsenide and has a maximum emission of 960 nm in the IR region with an optical power of 30 watts.

Combining it with the luminophores of the formula (I), (II), (III) or (IV) selected as a result of testing our method, allows us to obtain a visible light source with an optical power of up to 10 watts and an efficiency of 20%.

The source may additionally contain a reflector, wherein one or more LED chips are placed on a printed circuit board inside the reflector, and the phosphor is deposited on the reflector and / or dispersed on a light disk located above the reflector.

It is preferable to fill the LED chips with a transparent pouring mass. This casting mass forms, on the one hand, a mechanical protection; on the other hand, it also improves optical properties (increasing the yield of light from an LED crystal).

It is best to use silicon-inorganic varnish as the filling mass.

The luminescent light source may additionally contain a polymer lens, if possible without gas inclusions, and it is better if the polymer lens and the casting mass have refractive indices differing by no more than 0.1, and the phosphor is dispersed in the casting mass, which binds the micro-assembly of LED chips on printed circuit board. Due to similar refractive indices, there are almost no losses due to reflection on the interface.

To reduce the height of the mechanical assembly, the polymer lens may have a notch of a spherical or elliptical shape filled with a casting mass, so that the LED microassembly is fixed at a small distance from the polymer lens.

The phosphor can be suspended in a polymer lens.

The luminescent light source may contain an additional phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese, or from the group of alkaline earth magnesium disilicates: Eu ²⁺ , Mn ²⁺ , with the formula (V)

Where

0.005 <x <0.5; 0.005 <y <0.5

and Me = Ba, and / or Sr, and / or Ca,

or from the group of ternary compounds doped with europium and bismuth, with the formula (VI)

where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si), with the additional phosphor located spatially in the same region as the main phosphor, or placed relative to the main one after another in the direction of light propagation ..

In order to achieve uniform distribution of the phosphor, it is advisable to suspend the phosphor preferably in an inorganic matrix. When using at least two phosphors, it is advisable to separately suspend in the matrices at least two phosphors located one after another in the direction of light propagation. Due to this, it is possible to reduce the concentration of phosphors in comparison with the homogeneous dispersion of various phosphors.

Further advantages of the invention are explained below by way of example embodiments and drawings.

Figure 1-2 presents options for a luminescent source of visible light based on the proposed method, containing an incandescent lamp.

This source consists of a tungsten filament 1, fixed in the cap 2, inside the glass bulb 3. In figure 2, a reflector 4 is applied to the lower part of the glass bulb. It serves to increase the light flux emitted by the lamp.

Figures 3-4 show variants of a luminescent visible light source based on the proposed method comprising an LED, and Figures 5-8 show spectra (relative intensity I depending on wavelength) of various LED light sources according to this invention.

These sources consist of LED chips 1 of gallium arsenide, located on the printed circuit board 2. For the manufacture of lighting sources, it is advisable to use LED arrays instead of individual LEDs. In a preferred embodiment of the invention, the color formation is carried out on a matrix of LEDs 1 ′ (see FIG. 4), in which the LED crystals 1 are assembled directly on the circuit board 2, which are filled with a transparent casting mass 3, on the one hand, to protect the LED crystals and, with on the other hand, to provide improved output of the light created in the LED. This casting mass 3 may contain each crystal individually or may represent a common shape for all crystals. In Fig. 3, the printed circuit board 2 is inserted into the reflector 4, or the reflector is superimposed on top of the LED crystals 1. A light disk 5 is mounted on the reflector 4. It serves, on the one hand, to protect the microassembly; on the other hand, phosphors 6 can be introduced into this light disk.

During the operation of such a source, the infrared radiation from the LED chips 1 passing through the light disk 5, when passing through, is partially converted by the phosphor 6 into the second spectral region, so that a green glow is generally obtained. Losses due to the effects of waveguides arising in plane-parallel plates are reduced due to the opacity and scattering properties of the disk 5. Further, the reflector 4 ensures that the previously directed light enters the light disk 5, so that the effects of total reflection are immediately attenuated.

In Fig. 4, the printed circuit board 2 is adhered by means of a casting compound (3) (for example, epoxide) to a transparent polymer lens 7, which consists of another material (for example, PMMA (polymethylmethacrylate)). The materials of the polymer lens 7 and the casting mass 3 are selected so that their refractive indices are as close as possible, i.e. phase matched. The casting mass 3 is located in the recess of the most spherical or ellipsoidal shape of the polymer lens 7. The shape of the notch matters to the extent that the material for dispersion of color is dispersed in the casting mass 3. Therefore, by shaping, the creation of radiation colors independent of the angle can be achieved. As an alternative to this, the matrix can first be filled with a transparent casting mass, and then glued to the polymer lens using a casting mass, which contains material for color conversion. You can also apply the phosphor to the polymer lens 7.

When this source is working, infrared radiation from the LED chips 1 passes through the fill mass 3 and the light disk 5 with the anti-Stokes phosphor 6 dissolved in it. In the phosphor, infrared radiation is converted to visible with an energy efficiency of about 50%.

In a preferred embodiment, the formation of color is as follows:

- infrared radiation has a wavelength of 960 nm;

- anti-Stokes phosphor composition Y _1.9 O ₂ S: Er _0.05 , Yb _0.05 dispersed in a layer of silicon-inorganic varnish "Tsapon" in a volume ratio of 1: 1;

- ytterbium ions absorb infrared photons and transfer energy to erbium ions, where the energy of infrared photons and the emission of green and red photons with wavelengths of 555 nm and 670 nm are summed (Fig. 5).

For the manufacture of white LEDs with particularly good color reproduction, in which at least two different phosphors are used, it is advisable to disperse them not together in the matrix, but disperse and apply separately. This is especially true for combinations in which the final color of the light is created as a result of a multi-stage process of color formation. This means that the color of the longest wavelength radiation is generated in the process of radiation, which proceeds as follows: absorption of the LED radiation by the first phosphor - radiation of the first phosphor - absorption of the radiation of the first phosphor by the second phosphor and radiation of the second phosphor. It is especially preferable for a process of this kind to place individual materials one after another in the direction of light propagation, since this can reduce the concentration of materials in comparison with the homogeneous dispersion of various materials.

The invention is not limited to the described examples. Phosphors could also be introduced into a polymer lens (or other optics). You can also place the phosphor directly on top of the LED crystal or on the surface of the transparent casting mass (figure 3). The phosphor can also be introduced into the matrix together with scattering particles. This prevents the deposition of particles in the matrix and ensures uniform light output.

Figure 5 shows the emission spectrum of a green LED that arose as a result of a combination of an AL123A infrared LED emitting at a voltage of 1.5 V in the first spectral region with a center wavelength of 940 nm and a phosphor of formula (I) according to this invention having a composition of Y _1.9 O ₂ S: Er _0.05 , Yb _0.05 , emitting in the second spectral region with a maximum of 556 nm. One can also see the presence in the visible region of the electroluminescence spectrum of narrow peaks with peaks at 550 nm and 670 nm, as well as an infrared glow of 980 nm.

Figure 6 shows the excitation spectra of the visible emission bands of 550 nm (a), 556 nm (c) and 670 nm (s) of the phosphor of formula (I) according to this invention having the composition Y _1.9 O ₂ S: Er _0.05 , Yb _0.05 , in the infrared region of the luminescence spectrum (d) of the AL123A infrared LED.

7. typical electroluminescence spectra of a semiconductor light source are presented (using a luminescent material of formula (I) having the composition Y _1.9 O ₂ S: Er _0.05 , Yb _0.05 ) at different excitation levels. The power of the semiconductor source is provided by rectangular pulses from the G5-15 generator, the pulse duration is 10 μs, the pulse repetition period is 100 μs. The pulse voltage is 1.5 V (a), 2.0 V (v). When supplied with direct current, the spectral dependence of the radiation is close to the indicated spectra. An electroluminescent light source has a three-band emission spectrum in the visible region with characteristic bands at 550, 556 and 670 nm and a longer wavelength wide band at 980 nm.

On Fig presents examples of a combination of an LED emitting at a wavelength of 940 nm, with one phosphor based on yttrium oxosulfide according to this invention. If a phosphor emitting a greener light of 550 nm with a composition of Y _1.9 O _1.5 S _1.5 : Er _0.05 , Yb _0.05 (a) is used for color conversion, the color of a greener light can be set, while when using a phosphor with the composition Yi _1.9 O ₂ S: Er _0.06 , Yb _0.04 it is possible to produce a source of more yellow light (556 nm) with a very low intensity of the red band 670 nm (in). An increase in the proportion of ytterbium in the phosphor Y _1.9 O ₂ S: Er _0.04 , Yb _0.06 (s) leads to an increase in the intensity of the red band of 670 nm in the visible region of the spectrum of the light source.

Example 1. The method of preparation of phosphors.

For the manufacture of phosphors based on yttrium oxosulphides according to the selected composition, the starting materials — yttrium oxide, erbium oxide, and ytterbium oxide, which during the solid-phase reaction, which is usual for the manufacture of luminous paints, in a reducing atmosphere of hydrogen sulfide at temperatures ranging from 1100 ° C to 1400 ° C are converted into the desired phosphor. In the claimed invention, it is also possible to replace part of the oxides with sulfides by adding compounds of the above elements in appropriate stoichiometry amounts that can be thermally synthesized in an inert atmosphere. In a similar way, insignificant amounts of rare-earth metal ions can be incorporated into the corresponding crystal lattice.

The obtained phosphors based on yttrium oxosulfides according to this invention emit at wavelengths of about 980 nm, 660 nm and 550 nm and have several narrow lines with a peak half-width up to 10 nm (Fig. 5).

Due to the appropriate reaction parameters and due to certain changes in the concentrations of sulfur and oxygen, the particle size distribution of the phosphors according to this invention can be optimally adapted to the requirements of the respective application without using damaging mechanical grinding processes. In this way, it is possible to establish all narrow and broadband particle size distributions with average grain sizes d ₅₀ from about 2 μm to 20 μm.

Example 2. A method of producing visible light of green glow.

An incandescent lamp, the spectral range of which includes 350-1500 nm, is taken as a radiation source. As the phosphor, take the anti-Stokes phosphor of the formula (I) Y _1.90 O _1.5 S _1.5 : Er _0.05 , Yb _0.05 , the spectral absorption band of which 940-1020 nm (Fig.6) is close to the spectral band of the maximum infrared radiation of 1100 nm incandescent lamps. The phosphor was previously mixed in the glass of a glass bulb of an incandescent lamp. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 3. A method for producing visible light of yellow glow.

An incandescent lamp, the spectral range of which includes 350-1500 nm, is taken as a radiation source. As the phosphor, take the anti-Stokes phosphor of the formula (II) Y _1.9 O ₂ S: Er _0.04 , Yb _0.06 , the spectral absorption band (Fig.6) of which 940-1020 nm is close to the spectral band of infrared radiation of an incandescent lamp. The phosphor is applied to the outside of a glass bulb of an incandescent lamp. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 4. A method of producing visible light of green glow.

An incandescent lamp, the spectral range of which includes 350-1500 nm, is taken as a radiation source. As the phosphor, take the anti-Stokes phosphor of the formula (III) Y _1.91 O ₃ : Er _0.05 , Yb _0.04 , the spectral absorption band (Fig.6) of which 950-1010 nm is close to the spectral band of infrared radiation of an incandescent lamp. The phosphor is applied to the inside of a glass bulb of an incandescent lamp. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 5. A method of producing visible light with a yellow glow.

An incandescent lamp, the spectral range of which includes 350-1500 nm, is taken as a radiation source. As the phosphor, take the anti-Stokes phosphor of the formula (IV) Y _1.91 O ₃ : Er _0.04 , Yb _0.05 , the spectral absorption band of which 950-1010 nm (Fig.6) is close to the IR spectral band of the incandescent lamp. A reflective reflector layer is applied to the lower part of the glass bulb of the incandescent lamp (Fig. 2) and the phosphor is applied to the reflector. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 6. A method of producing visible light with a yellow glow.

An incandescent lamp, the spectral range of which includes 350-1500 nm, is taken as a radiation source. As the phosphor, take the anti-Stokes phosphor of the formula (IV) Y _1.91 O ₃ : Er _0.04 , Yb _0.05 , the spectral absorption band of which 950-1010 nm (Fig.6) is close to the IR spectral band of the incandescent lamp. A reflective reflector layer is applied to the lower part of the glass bulb of the incandescent lamp (FIG. 2) and the phosphor is dispersed onto the upper part of the glass bulb of the lamp placed above the reflector. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 7. A method for producing visible light of orange glow.

The same as in example 6, only a phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese Ca _0.95 Al ₂ O ₄ : Eu _{0.05 is} added only to the anti-Stokes phosphor.

Moreover, the additional phosphor is spatially located in the same region as the main one. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 8. A method of obtaining visible light of orange glow.

The same as in example 6, only a phosphor emitting red light Y _1.94 O ₂ S: Eu _0.03 , Bi _{0.03 is} added to the anti-Stokes phosphor only. Moreover, the additional phosphor is located relative to the main one after another in the direction of light propagation. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 9. A method for producing visible light of orange glow.

The same as in example 6, only to the anti-Stokes phosphor is added a phosphor emitting red light from the group of alkaline earth magnesium disilicate: Eu ²⁺ , Mn ²⁺ , with the formula (V) Ca _2.94 MgSi ₂ O ₈ : Eu _0.03 , Mn _0.03 , the additional phosphor being located relative to the main one after another in the direction of light propagation. When you turn on the incandescent lamp, part of its infrared radiation is converted into visible light, increasing its brightness by about 20-25%.

Example 10. A method of producing visible light of green glow

An LED containing a matrix of LED chips made of gallium arsenide, the spectral range of which is 940-1000 nm, is taken as a radiation source (Fig. 5). As the phosphor, take the anti-Stokes phosphor of the formula (I) Y _1.9 O _1.5 S _1.5 : Er _0.05 , Yb _0.05 , the spectral absorption band of which 940-1020 nm is close to the spectral band of the IR radiation of the LED. The phosphor was previously dispersed in the fill mass of the LED. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a bright glow (Fig. 7) with an optical power of up to 10 watts and an efficiency of 20%.

Example 11. A method of producing visible light with a yellow glow.

An LED containing a matrix of LED chips made of gallium arsenide, the spectral range (Fig.6) of which is 940-1000 nm, is taken as a radiation source. As the phosphor take the anti-Stokes phosphor of the formula (II) Y _1.9 O ₂ S: Er _0.04 , Yb _0.06 , the spectral absorption band of which 940-1020 nm is close to the spectral band of the infrared radiation of the LED (Fig.6). The phosphor was previously dispersed in the fill mass of the LED. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a bright glow (Fig. 7) with an optical power of up to 10 watts and an efficiency of 20%.

Example 12. A method of producing visible light of green glow.

An LED containing a matrix of LED chips made of gallium arsenide, the spectral range of which is 940-1000 nm, is taken as a radiation source. As the phosphor take anti-Stokes phosphor of the formula (III) Y _1.91 O ₃ : Er _0.05 , Yb _0.04 , the spectral absorption band of which 950-1010 nm is close to the spectral band of infrared radiation of the LED (Fig.6). The phosphor was previously dispersed in the fill mass of the LED. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a bright glow (Fig. 7) with an optical power of up to 10 watts and an efficiency of 20%.

Example 13. A method of producing visible light with a yellow glow.

An LED containing a matrix of LED chips made of gallium arsenide, the spectral range of which is 940-1000 nm, is taken as a radiation source. As the phosphor, an anti-Stokes phosphor of the formula (IV) Y _1.91 O ₃ : Er _0.04 , Yb _0.05 , the spectral absorption band of which 950-1010 nm is close to the spectral band of the IR radiation of the LED, is taken. A reflective reflective layer is applied to the lower part of the LED (Fig. 3) and a phosphor is applied to the reflector. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a bright glow (Fig. 7) with an optical power of up to 10 watts and an efficiency of 20%. In this case, the reflector increases the brightness in the forward direction.

Example 14. A method of obtaining visible light of yellow glow

An LED containing a matrix of LED chips made of gallium arsenide, the spectral range of which is 940-1000 nm, is taken as a radiation source. As the phosphor, an anti-Stokes phosphor of the formula (IV) Y _1.91 O ₃ : Er _0.04 , Yb _0.05 , the spectral absorption band of which 950-1010 nm is close to the spectral band of the IR radiation of the LED, is taken. A reflecting layer-reflector is applied to the lower part of the LED (Fig. 3) and the phosphor is dispersed in a light disk placed above the reflector. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a bright glow (Fig. 7) with an optical power of up to 10 watts and an efficiency of 20%.

Example 15. A method for producing visible light of orange glow.

The same as in example 14, only a phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese Ca _0.95 Al ₂ O ₄ : Eu _{0.05 is} added only to the anti-Stokes phosphor.

Moreover, the additional phosphor is spatially located in the same region as the main one. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a redder visible glow.

Example 16. A method of obtaining visible light of orange glow.

The same as in example 14, only to the anti-Stokes phosphor is added a phosphor emitting red light from the group of ternary compounds doped with europium and bismuth with the formula (VI)

YVO ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi,

Example 17. A method of obtaining visible light of orange glow.

The same as in example 16, only as an additional phosphor of the formula (VI) take YPO ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi.

Example 18. A method for producing visible light of orange glow.

The same as in example 16, only as an additional phosphor of the formula (VI) take YSiO ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi. Moreover, the additional phosphor is located relative to the main one after another in the direction of light propagation. When the LED is turned on (supply voltage 1.2-1.5 Volts), part of its infrared radiation is converted into visible light, giving a redder visible glow.

Example 19. A method for producing visible light of orange glow.

The same as in example 14, only a phosphor emitting red light from the alkaline earth magnesium disilicate group is added to the anti-Stokes phosphor only: Eu ²⁺ , Mn ²⁺ , with the formula (V) Ca _2.94 MgSi ₂ O ₈ : Eu _0.03 , Mn _0.03 , the additional phosphor being located relative to the main one after another in the direction of light propagation. When the LED is turned on, part of its infrared radiation is converted into visible light, giving a redder visible glow.

Example 20. A method of producing visible light of green glow

The same as in example 10, only additionally the light source contains a polymer lens, if possible without gas inclusions (figure 4). Moreover, the polymer lens and the casting mass have refractive indices differing by no more than 0.1, and the phosphor is dispersed in the casting mass.

Example 21. A method for producing visible light of green glow.

Everything is as in example 20, only the polymer lens has a recess of a spherical or elliptical shape, filled with a casting mass so that the LED microassembly is fixed at a small distance from the polymer lens, and the phosphor is suspended in the polymer lens.

As can be seen from the above examples, our proposed method for producing visible light and light sources based on it allow us to obtain powerful and compact visible light sources with a low operating voltage (supply voltage 1.2-1.5 Volts), increased brightness and with a high coefficient of useful 20% action.

Claims (21)

1. A method of producing visible light, including irradiating an anti-Stokes phosphor with infrared radiation, characterized in that the irradiation is carried out by radiation in the spectral range 940-1030 nm, and at least one inorganic material with an absorption spectral band close to spectral band of infrared radiation. 2. The method according to claim 1, characterized in that the yttrium oxosulfide of the formula activated by trivalent erbium and ytterbium is taken as an inorganic material (I) or (II) or mixtures of these formulations:

 where 0.01 <x <0.05; 0.005 <y <0.05; x≥y; x + y <0.1, 0.5 <a <1.5; b)

Where 0.01 <x <0.05; 0.01 <y <0.05; x <y; x + y <0.1; 0.5 <a <1.5. 3. The method according to claim 1, characterized in that as the inorganic material is taken activated by trivalent erbium and ytterbium yttrium oxide of the formula (III) or (IV) or a mixture of these compositions: a)

where 0.01 <x <0.05; 0.005 <y <0.05; x≥y; x + y <0.1 b)

where 0.01 <x <0.05; 0.01 <y <0.05; x <y; x + y <0.1. 4. The method according to any one of claims 2 and 3, characterized in that a phosphor emitting red light from the group of alkaline-earth metal aluminates activated by divalent europium and / or manganese, or from the group of alkaline-earth disilicates is additionally added to the anti-Stokes phosphor; magnesium: Eu ²⁺ , Mn ²⁺ , with the formula (V)

where 0.005 <x <0.5; 0.005 <y <0.5 and Me = Ba, and / or Sr, and / or Ca, or from the group of ternary compounds doped with europium and bismuth, with the formula (VI) Y (Me) O ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi, where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si), and the additional phosphor is spatially located in the same region as the main phosphor. 5. The method according to claim 1, characterized in that the irradiation is carried out by radiation in the spectral range with a maximum of 960 nm. 6. Luminescent source of visible light containing an incandescent lamp, characterized in that it further comprises an anti-Stokes phosphor containing at least one inorganic material with a spectral absorption band close to the infrared spectral band, and the spectral range of the incandescent lamp includes a range 940-1030 nm. 7. The luminescent source of visible light according to claim 6, characterized in that at least one of the compounds of the formula (I), (II), (III) or (IV) is taken as the phosphor. 8. The luminescent light source according to claim 6, characterized in that the phosphor is mixed in the glass of a glass bulb of an incandescent lamp. 9. The luminescent light source according to claim 6, characterized in that the phosphor is applied to the outer part of the glass bulb of an incandescent lamp. 10. The luminescent light source according to claim 6, characterized in that the phosphor is deposited on the inside of a glass bulb of an incandescent lamp. 11. The luminescent light source according to claim 6, characterized in that a reflective reflector layer is deposited on the lower part of the glass bulb of the incandescent lamp and the phosphor is deposited on the reflector and / or dispersed on the upper part of the glass bulb of the lamp placed above the reflector. 12. The luminescent light source according to claim 6, characterized in that it contains an additional phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese, or alkaline earth magnesium disilicate: Eu ²⁺ , Mn ²⁺ , with the formula (V)

where 0.005 <x <0.5; 0.005 <y <0.5 and Me = Ba, and / or Sr, and / or Ca, or from the group of ternary compounds doped with europium and bismuth, with the formula (VI) Y (Me) O ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi, where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si), moreover, the additional phosphor is spatially located in the same region as the main phosphor, or placed relative to the main one after another in the direction of light propagation. 13. Luminescent source of visible light containing an LED and at least one phosphor, characterized in that an LED containing a gallium arsenide LED chip is used as an LED, and an anti-Stokes phosphor containing at least at least one is used , one inorganic material with a spectral absorption band close to the IR spectral band. 14. The luminous source of visible light according to claim 13, characterized in that at least one of the compounds of formula (I), (II), (III) or (IV) is taken as the phosphor. 15. The luminescent light source according to claim 13, characterized in that the source further comprises a reflector, wherein one or more LED chips are placed on a printed circuit board inside the reflector, and the phosphor is deposited on the reflector and / or dispersed on a light disk located above the reflector. 16. The luminescent light source according to claim 13, characterized in that the LED chips are flooded with a transparent casting mass that binds the microassembly of the LED chips on a printed circuit board. 17. The luminescent light source according to clause 16, characterized in that a silicon-organic varnish is used as the casting mass. 18. The luminescent light source according to claim 13, characterized in that it further comprises a polymer lens, possibly without gas inclusions, the polymer lens and the casting mass having refractive indices differing by no more than 0.1, and the phosphor is dispersed in the casting mass. 19. The luminescent light source according to claim 18, wherein the polymer lens has a spherical or elliptical recess filled with a casting mass such that the LED microassembly is fixed at a small distance from the polymer lens. 20. The luminescent light source according to claim 18, wherein the phosphor is suspended in a polymer lens. 21. The luminescent light source according to 14, characterized in that it contains an additional phosphor emitting red light from the group of alkaline earth metal aluminates activated by divalent europium and / or manganese, or alkaline earth magnesium disilicate: Eu ²⁺ , Mn ²⁺ , with the formula (V)

where 0.005 <x <0.5; 0.005 <y <0.5 and Me = Ba, and / or Sr, and / or Ca, or from the group of ternary compounds doped with europium and bismuth, with the formula (VI) Y (Me) O ₄ : Eu, Bi, Y ₂ O ₂ S: Eu, Bi, where Me is one of the group of metals vanadium (V), phosphorus (P) or silicon (Si), moreover, the additional phosphor is spatially located in the same region as the main phosphor, or placed relative to the main one after another in the direction of light propagation.

Images