Phosphor conversion light - emitting diode for meeting photomorphogenetic needs pf plants

The present invention relates to solid-state light sources whose radiation spectrum meets specific photomorphogenetic needs of plants. More particularly, the present invention discloses an LED in which the light generated by the semiconductor chip is partially or completely converted in a phosphor-containing converter containing carbon. phosphor - a substance that converts radiation of shorter wavelength into radiation of longer wavelength) with a spectral peak in the far red region between about 700 nm and 760 nm corresponding to the plant photoreceptor Pf_r shape absorption spectrum of phytochrome.

The present invention relates directly to artificial lighting for crop production based on solid-state technology.

Photo physiological processes in plants are controlled by phytopigments (chlorophylls, carotenoids, phytochromes, cryptochromes), which efficiently use photons only in specific wavelength bands. Specifically, chlorophylls require light in the wavelength range from 620 nm to 680 nm, carotenoids absorb light in the region of 450 nm, different phytochrome forms of P_r and Pf_r are excited by light with wavelengths of 660 nm and 730 nm, respectively, and the cryptochromes absorb light in the range 340 nm and 520 mn [MS Mc Donald, Photobiology of Higher Plants (Wiley, Chichester, 2003), xiv + 354, ISBN 0470855223] . Meanwhile, light with wavelengths shorter than 400 nm and longer than 800 nm can adversely affect plant morphogenesis. Therefore, the efficiency of artificial plant lighting can be enhanced by using light sources with only narrow bands in blue (ca. 450 nm), red (ca.

660 nm) and far red (about 730 nm) spectral regions.

One method of optimizing the lighting spectrum of plants has been implemented using fluorescent lamps, which are low pressure mercury vapor discharge lamps with phosphor coating. Ultraviolet (UV) light (254 nm), which is generated in a discharge, can be converted to phosphorus at other wavelengths in the same manner as in white fluorescent lamps, but with increased flux in said spectral bands of importance to plants [U.S. Patents No. 3,287,586 (1963). ); 3,992,646 (1976); 4,371,810 (1983); 5,525,860 (1996); 7,259,509 (2007)]. However, fluorescent lamps have many disadvantages that prevent them from being widely used in crop production. First, the fluorescent lamps have physical limits · which are due to the limited UV light generation efficiency of low pressure mercury vapor discharge (about 63%) and the high Stokes shift in converting UV light to visible light (ie when 254 nm is converted to 450 nm, 660 nm, or 730 nm Light, inevitably above 40%, above 60% and above 65% of energy respectively). This means that the total fluorescent lamp's efficiency in generating important light for plants cannot exceed 25%, while in the far red area it can only reach 22%. In addition, fluorescent lamps contain mercury, a hazardous substance, typically have an effective lifetime of less than 20,000 hours, are showers, use high voltages, and emit unwanted infrared light.

Another way of optimizing the spectrum of plant lighting, which significantly reduces the main disadvantages of fluorescent lamps, is the use of solid-state light sources - light emitting diodes (LEDs). LEDs are based on the principle of injectable electroluminescence, the performance of which is not limited by physical factors. Therefore, potentially, luminaires can be more efficient than other light sources. In addition, the luminaires are superior in mechanical strength, small dimensions, durability (up to. 100 000 hours), fast switching, fast burnout, low power supply voltage (2-4V), compatible with computer electronics, emitting narrow spectral bands without unwanted spectral components, free of hazardous materials (mercury) and flexible in mounting on various shapes point of view. This results in the solid state lighting technology based on luminaires gradually penetrating all areas of artificial light application, including crop production [A. Žukauskas, MS Shur, R. Gaška, Introduction to Solid State Lighting (Wiley, New York, 2002), xii + 207 pp., ISBN 0471215740].

The spectrum of light emitted by LEDs can be adapted to meet the photophysiological needs of plants in several ways. The first way is to use the optoelectronic principle (electroluminescence injection) directly, where the wavelength of the light emitted is determined by the energy of the gap in the active layer of the LED, which can be changed by varying the chemical composition of the semiconductor alloy.

This allows fine-tuning of narrow-band LED illumination with absorption spectra of phytopigments. Shortly after the development of high luminance AlGaAs, it was proposed to increase the photosynthetic productivity of plants by illumination with quasimonochromic light, which is compatible with the chlorophyll absorption spectrum (at 660 nm) so as to avoid the energy loss inherent in shorter wave absorption [Bula RJ, Morrovv RC , Tibbitts TW, Barta DJ, Ignatius RW, Martin T. S., "Light-emitting diodes as a radiation source for plants," HortScience 26 (2), p. 203-205 (1991)]. Subsequent U.S. Patent No. 5,012,609 (1991) defined three spectral stretches covered by a matrix of colored optoelectronic devices that are required for plant growth and morphogenesis, namely, 620-680nm for photosynthetic needs of plants and 700-760nm for photomorphogenetic needs. 500 nm - for phototropic and photomorphogenetic needs. Subsequently, it has been proposed to introduce into green matrices for plant cultivation and other types of electroluminescent light emitting green and UV light [U.S. Pat. 6,725,598 (2004)] as well as an orange light [U.S. Pat

No. 6,921,182 (2005)] to induce specific plant photophysiological responses.

Although arrays of electroluminescent LEDs emitting at individual wavelengths driven by the active layer resin gap energy are very flexible and potentially efficient crop-based luminaires, they have some inherent drawbacks, which are mainly due to the installation of LEDs made from different semiconductors into one light source. For example, LEDs with an active layer made of different semiconductors have different power voltages, which are determined by the energy and the series impedance of the semiconductor gap. This complicates the use of common power supplies for all LED groups and requires separate power circuits for each LED type. Second, different types of luminaires have different temperature output coefficients and different degradation rates. Such uneven thermal and aging drifts cause partial photonic fluxes of different spectral components to vary with temperature and lifetime. For example, the radiation performance of AlGaAs and AlGalnP semiconductors, which are used in red LEDs, is limited and highly sensitive to temperature due to the side valleys in the conduction band, unlike blue InGaN LEDs, which do not have this disadvantage. Thirdly, some of the semiconductors, such as AlGaAs and AlGalnP, use highly toxic materials (arsenic As, arsine AsK, phosphine P1-a) which are environmentally undesirable.

An alternative method of solid state illumination is the application of phosphor (luminophore) conversion lamps. In phosphor conversion luminaires, in addition to the principle of electroluminescence, the principle of photoluminescence is used, in which the shortwave (blue or near UV) radiation generated by a semiconductor chip is partially or completely converted to the required wavelength transducer using the required phosphorus. Such LEDs are solid-state equivalents of fluorescent lamps, but they have a number of advantages over both fluorescent lamps and pure electroluminescent lamps. Compared to fluorescent lamps, their performance can be much higher, since the primary light source is not limited by physical factors and can reach 100%. Also, due to the longer wavelength generated in the primary source, the light conversion efficiency can be much higher. For example, converting 450 nm wavelength light to 730 nm wavelength can result in a conversion efficiency of 62%, while converting the same light to 660 nm wavelength can yield up to 68% efficiency. Meanwhile, compared to pure electroluminescent LED arrays, phosphor conversion LEDs avoid temperature-sensitive and limited performance AlGaAs and AlGalnP. use of lights. Since phosphor conversion LEDs can only be manufactured from one type of semiconductor such as InGaN, this allows the power supply of the light emitting luminaires of different wavelengths to be uniform. In addition, the non-metallic nitrogen (N) precursor used in InGaN semiconductor production is usually ammonia (NH3), which is much less toxic than the arsenic (As) and phosphorus (P) precursors used in AlGaAs and AlGalnP. Also, InGaN semiconductor based LEDs may be more durable than AlGaAs and AlGalnP equivalents because their active layer does not contain chemically reactive aluminum (Al). Finally, phosphor conversion lamps can simultaneously generate light with multiple narrowband components using only one type of semiconductor chip and a single power supply.

Conventional phosphor conversion lamps, like fluorescent lamps, are used to generate white light. In white partial conversion phosphor lamps [U.S. Pat. 5,998,925 (1999)] a portion of the blue light generated by an InGaN chip is converted to yellow light using garnet-type phosphorus activated by trivalent cerium ions. The resulting mixture of blue and yellow light is perceived by the human eye as white light. In white full conversion phosphor luminaires [U.S. Pat. 6,084,250 (2000)] employs a near-UV-generating semiconductor chip and a mixture of phosphorus of different chemical compositions to emit blue, green, and red light. White phosphor conversion LEDs are widely used for backlighting, signaling, lighting, and measurement technology in liquid crystal displays. Such LEDs are also sometimes incorporated into plant matrix LEDs as sources of additional spectrum components (e.g., yellow) [U.S. Pat. 6,725,598 (2004)]

Most white phosphor conversion LEDs emit one or more spectral components that are suitable for some plant photophysiological needs. For example, all white partial conversion phosphor lamps [for example, U.S. Pat. 5,998,925 (1999); 6,252,254 (2001); 6,501,102 (2002); 6,504,179 (2003); 6,982,045 (2006); 7,038,370 (2006)], the primary spectrum component generated by the InGaN semiconductor chip has a peak in the blue region between 400 nm and 500 nm, which corresponds to the optical absorption spectrum of carotenoids and cryptochromes. The blue spectrum also emits most white full conversion LEDs using phosphores such as BaMgAlioOi7: Eu²⁺ [U.S. Pat. 6,084,250 (2000)], (Sr, Ba, Ca) 5 (PO4) 3 Cl: Eu²⁺ and BaMg2Ali₆O₂7: Eu²⁺ [U.S. Pat. 6,294,800 (2001)], La 3 Si 6 Nn: Ce³⁺ and SrSiAl₂O3N₂Ce³⁺ [U.S. Pat. 6,670,748 (2003)] and others. Some white partial conversion LEDs have wavelength converters that emit in the red region between 620 nm and 680 nm, which corresponds to chlorophyll and P_r For example, Y is used for this purpose₂O₂S: Eu³⁺, Bi³⁺, YVO4: Eu³⁺, Bi³⁺ and SrY2S₄: Eu²⁺ [U.S. Pat. 6,252,254 (2001)], SrS: Eu²⁺ [U.S. Pat. 6,501,102 (2002)], CaS: Eu²⁺ and Sr₂Si₅N₈: Eu²⁺ [U.S. Pat. 7,038,370 (2006)] phosphorus. Many white LEDs of complete conversion to phosphor also emit in the same plant red spectrum. Phosphores such as Y are used for this₂O₃: Eu³⁺, Bi³⁺ [U.S. Pat. 6,294,800 (2001)], MgO-MgF2-GeO2: Eu²⁺ [U.S. Pat. 6,621,211 (2003)], Sr 2 Si₄A10N₇: Eu²⁺ [U.S. Pat. 6,670,748 (2003)]. The latter class of oxynitride phosphorus can be precisely matched to the absorption spectrum of chlorophylls.

However, conventional white phosphor conversion LEDs cannot fully meet the photophysiological needs of plants because they are adapted for visual applications and lack the spectrum component in the far red region (700-760 nm), which is necessary for reverse Pf_r forms for excitation of phytochrome. For visual applications, far-red components of the spectrum are avoided because red radiation at wavelengths above 660 nm has poor luminosity, meaning that the sensitivity of the eye in this spectrum is poor compared to the 640-660 nm spectrum, where the color perception of red light is same. Meanwhile, phytochrome reverse excitation plays a key role in a number of photomorphogenetic processes, such as diurnal cycle determination, germination, stem height and leaf number and shape regulation, flowering, chlorophyll synthesis, and so on.

The closest prototype for the proposed phosphorus conversion LED for plant photomorphogenetic needs is the above-mentioned InGaN white light illuminator based on a semiconductor chip and a trivalent cerium ion-activated garnet disclosed in U.S. Pat. 5,998,925 (1999).

However, this luminaire cannot fully meet the photophysiological needs of plants because it is adapted for visual applications and lacks the spectral component in the far red region (700-760 nm), which is necessary for reverse P_t-_r for excitation of phytochrome.

It is an object of the present invention to provide phosphor conversion lamps employing partial conversion of blue light or full-beam UV light in a wavelength converter such that the resulting light has a spectral component with a peak in the 700-760 nm wavelength band required for Pf._r forms for excitation of phytochrome.

The object of the present invention is achieved by a light-emitting diode (LED) housing a semiconductor chip which generates shortwave radiation at a wavelength of less than 500 nm by injection electroluminescence and a transducer arranged in the path of the photon beam emitted by said chip for converting said radiation into longer wavelengths. due to photoluminescence and containing at least one type of phosphor particles. What is new is that the transducer contains phosphorus with a spectral peak in the far red region between about 700 nm and 760 nm, corresponding to the plant photoreceptor phytochrome P |_rshape absorption spectrum such as

- lithium aluminate activated by trivalent iron ions,

- gadolinium and gallium oxide activated by trivalent chromium and / or trivalent cerium ions, or

- Calcium sulphide activated by divalent iterbium ions.

In the case of partial conversion, the semiconductor chip generates blue light in the 400-500 nm spectrum, which satisfies the photomorphogenetic and phototropic needs of the plants, and the transducer is characterized by the partial conversion of this light into longer-wave light.

In the case of full conversion, the semiconductor chip generates near-UV or violet or blue light with a wavelength of less than .500 nm, and the transducer has full conversion of this optical radiation to light of longer wavelengths.

For both partial conversion and total conversion, the transducer may contain additional phosphorus, which emits red light in the 620-680 nm spectral range, meeting plant photosynthetic and photomorphogenetic needs, such as an oxide, halooxide, chalcogenide, or nitride compound activated by divalent or quaternary manganese, divalent or trivalent european, trivalent bismuth, or divalent tin ions.

In the case of complete conversion, the transducer may contain additional phosphorus that emits blue light in the 400-500 nm spectral range, which satisfies the photomorphogenetic and phototropic needs of plants such as an oxide, halo, or nitride compound activated with divalent europium, divalent manganese, divalent tin, or trivalent j onais.

In the case of partial conversion, the wavelength converter has either only one phosphor which partially converts the blue light to the far red light or multiple phosphores which partially converts the blue light to the far red light and red light.

In the case of full conversion, where the semiconductor chip generates near-UV light, the wavelength converter contains either only one phosphor that completely converts the near-UV light to the far-red light, or multiple phosphores that completely convert the near-UV light to the far-red and red light. , or only to the high beam red light and blue light or to the high beam red light, red light and blue light.

In the case of full conversion, where the semiconductor chip generates blue light, the wavelength converter has either only one phosphor which completely converts blue light to far red light, or multiple phosphores which completely converts blue light to far red light and red light.

In the case of partial conversion, the semiconductor chip emits blue light in the 400-500 nm spectral band and has an active layer made of In_xGai__xN semiconductor alloy.

For full conversion, the semiconductor chip is emitted at a wavelength shorter than 500 nm and has an active layer made from a GaN semiconductor compound or In._xGai__xN, Al_yGai__yN or Al_yIn_xGai__x__yN semiconductor alloy.

In either of the above cases, where a light emits multiple components of the spectrum, the partial photon fluxes and the peak wavelengths of each component of the spectrum are selected such that the final spectral composition of the emitted light is suitable for operation solely or together with other sources. specific greenhouse plants such as lettuce, cucumbers, tomatoes, radishes, carrots, onions, cauliflowers, broccoli, green peas, wheat or barley greens, etc.

The components of the generated light spectrum have the following partial photon fluxes: about 1: 4 when the illuminator emits only the far red and blue light respectively, about 1:15 when the illuminator emits only the far red and red light respectively, about 1: 15: 4 when The LED emits a far-red, red, and blue light, respectively.

The partial photon fluxes of each component of the spectrum are determined by selecting the size and concentration of the phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, the distance between the wavelength transducer and the electroluminescent structure and the wavelength transducer position inside the luminaire housing.

Optically, the generated light spectrum components have the following peak wavelengths:

about 730 ± 20 nm for the far red component, about 660 ± 20 nm for the red component, about 450 ± 20 nm for the blue component.

In addition, the wavelength transducer may have additional phosphorus emitted in the yellow, yellow-green, green, or green-blue areas such that the light generated by the LED is perceived by the human vision as a particular color, such as white light with a correlated color temperature. .

The advantages of the present invention are set out below, after a detailed explanation of the invention.

The invention is explained in the drawings, in which:

Fig. 1 - Basic structure of a partial conversion of blue light into phosphorus for crop production.

Figure 2 - Basic structure of a phosphor light for total crop conversion of dipped UV light.

Figure 3 - Typical electroluminescence spectra of a semiconductor chip with an InGaN active layer: (a) blue emitter; (b) Near-UV emitter.

Fig.4 - Typical photoluminescence spectra of inorganic phosphorus: (a) 10 far red region emitter; (b) red emitter; (c) Blue emitter.

Fig.5 - Radiation spectra of partial phosphor conversion LEDs for crop production: (a) blue-far-red LED; (b) Blue-red-far-red light.

Fig.6 - Radiation spectra of complete phosphor conversion LEDs for crop production: (a) Far red LED; (b) a blue flashing red light; (c) red-far-red light; (d) Blue-red-far-red light.

The proposed illuminator consists of a semiconductor chip 1; 14 (Fig. 1; Fig. 2) generating shortwave radiation at a wavelength of less than 500 nm by injection electroluminescence contained in a reflector cup 2; 15 and connected to the terminals 3; 16 wires 4; 17. Chip 1; 14 is covered by a wavelength converter 5; 18, enclosed in a transparent housing 6; 19th The aforesaid transducer is intended for the conversion of said radiation into longer-wave radiation due to photoluminescence, and has at least one type of phosphor (luminophore) particles 7; 21, and may also have additional phosphor particles 8, 24, 27. Photons shown in positions 9. 10, 11 , 12, 13; 20, 22.23, 25, 26.28.

The partial conversion of blue light to phosphor has a semiconductor chip 1 (Fig. 1) emitting blue light in the 400-500 nm spectral band, which satisfies the photomorphogenetic and phototropic needs of plants. This blue light is also matched to the phosphor absorption spectrum of the transducer 5. A portion of the primary flux is converted by suitable phosphorus 7 into the far red light in the 700-760 nm spectrum, which corresponds to the plant photoreceptor phytochrome P_fr shape absorption spectrum. Meanwhile, the remainder of the primary blue light, which satisfies the phototropic and photomorphogenetic needs of the plants, remains intact.

A complete conversion of dipped UV light in phosphor has a semiconductor chip 14 (Fig. 1) emitting dipped UV, violet or blue light with wavelengths shorter than 500 nm. This light is tuned to the absorption spectra of the phosphorus and is fully convertible in the wavelength converter 18. The converter 18 contains phosphorus 21, which converts shortwave radiation to far red light in the 700-760 nm spectrum, which corresponds to phytochrome P of the plant photoreceptor._ft shape absorption spectrum.

In addition to the phosphorus emitting in the far red region, the wavelength converter of such luminaires may have additional phosphorus 8, 24, 27 emitted in other spectral regions important for plant growth and development. Phosphorus conversion luminaires for crop production can employ a wide variety of available phosphorus [Inorganic Phosphors. Compositions. Preparation and Optical Properties, edited by WM Yen and MJ Weber (CRC Press, Boca Raton, 2004), 475 pp., ISBN 0849319498; R. Mueller-Mach, G. Mueller, MR Krames, HA Hoppe, F. Stadler, W. Schnick,

T. Juestel, and P. Schmidt, Phys. Status Solidi A, 202 (9), p. 1727-1732 (2005); U.S. Pat. 6,084,250 (2000), 6,252,254 (2001), no. 6,294,800 (2001), no. 6,501,102 (2002), no. 6,621,211 (2003), no. 6,670,748 (2003), No. 7,038,370 (2006)]. The position of the spectral peaks of the phosphorus and the bandwidths are consistent with the absorption spectra of the phytopigments by selecting the chemical composition of the parent crystal and the type of activator ion.

The total or partial conversion of phosphor to the luminaire converter 5; 1S may contain additional phosphorus 8, 24 which absorbs part of the wavelength below 500 nm and emits red light in the 620-680 nm spectrum, which meets the photosynthetic and photomorphogenetic needs of plants. Such phosphorus may be an oxide, halooxide, chalcogenide, or nitride compound activated by divalent or quaternary manganese, divalent or trivalent europium, trivalent bismuth or divalent tin ions. For example, an additional red component can be generated in inorganic phosphorus such as Mg₂SiO₄: Mn²⁺, Mg4 (F) GeO6: Mn²⁺, (Mg, Zn) 3 (PO)₄: Mn²⁺, Y3Al50i2: Mn⁴⁺, (Ca, Sr, Ba) 2Si₅N₈: Eu²⁺, Sr2Si4A10N7: Eu²⁺, MgO-MgF2-GeO₂: Eu²⁺, Y2O2S: Eu³⁺, Bi³⁺, YVO4: Eu³⁺, Bi³⁺,

Y₂O₃: Eu³⁺, Bi³⁺, SrY2S4: Eu²⁺ SrS: Eu²⁺ with MgSr5 (PO)₄: Sn²⁺.

The complete phosphor conversion in the LED converter 18 may contain additional phosphor

27, which absorbs part of the radiation at wavelengths shorter than 430 nm and emits blue light in the 400-500 nm spectrum, which satisfies the photomorphogenetic and phototropic needs of plants. Such phosphorus may be an oxide, halooxide, or nitride compound activated with divalent europium, divalent manganese, divalent tin, or trivalent cerium ions. For example, an additional blue component may be generated in inorganic phosphorus such as CaMgSi₂O6: Eu²⁺,

Ba₅SiO₄Cl₆: Eu²⁺, Mg3Ca3 (PO4) 4: Eu²⁺, (Ca, Sr, Ba) 5 {PO₄)₃Cl: Eu²⁺,

Ca.₂B₅O9 (Br, Cl): Eu²⁺, BaMgAli0O17: Eu²⁺, Mn²⁺, BaMg2Al₁₆O₂₇: Eu²⁺, (Lu, Gd)₂SiO₃: Ce³⁺, Sr2P2O7: Sn²⁺, SrSiAl2O₃N₂: Ce³⁺, or La₃Si₆N ,,: Ce³⁺.

The partial conversion phosphor can have either two components (blue and far red) or all three components (blue, red and far red).

For a full conversion phosphor, the spectrum of light emitted by semiconductor chip 14 emitting wavelengths shorter than 430 nm may contain either one component (far red) or two components (blue and far red or red and far red) or all three components (blue) , red, and far red).

The full-phosphor conversion spectrum of LEDs in which the semiconductor chip 14 generates 430-500 nm wavelength radiation has either a single component (far red) or two components (red and far red).

Phosphor Conversion The LED has a conventional design semiconductor chip

1; 14, consisting of a p-type layer connected to the anode terminals and an n-type layer connected to the cathode terminals 3; 16, which overlays the active layer. In the active layer, electrons injected from a n-type envelope recombine with holes injected from a p-type envelope.

The semiconductor chip 1; 14 of the exposed phosphor conversion LEDs has an active layer that emits blue or dipped UV light. In the active layer, it is preferable to use the third group of nitride compounds having the general formula Ayn_xGai__x_ ^ N. These materials have a high chemical and photochemical inertness, which determines the durability of LEDs. The structure of these semiconductor energy bands (remote side valleys) and the characteristics of charge recombination result in a weak temperature dependence of the output stream. The thickness of the active layer and the molar portions of the indium and / or aluminum, x and y, respectively, are selected such that the peak of the emission band is at the desired wavelength.

Partial Conversion In Phosphor For LEDs in which a semiconductor chip 1 emits in the 400-500 mn wavelength range, the most suitable active layer material is triple In._xGa, ^ N alloy.

For complete conversion of phosphor in luminaires in which the semiconductor chip 14 5 emits at a wavelength of less than 500 nm, the active layer can be made from triple In_xGa |._xN alloy (wavelength range 370-500 nm), binary GaN compound (wavelength about 360 nm), or triple Al ^ Gai ^ N alloy (wavelengths shorter than 360 nm). Also, a quadruple Al can be used throughout the wavelength range_yIn_xGai__x_yN alloy.

Typically, the chip 1, 14 is mounted in a reflector cup 2; 15 and wire 4;

connects to metal terminals 3; 16 through which chip 1; 14 is powered by current. Wavelength converter 5; 18, which is a resin layer, a crystalline or ceramic plate, or a plastic mold containing phosphor particles, is disposed adjacent to the semiconductor chip 1; 14 such that part or all of the photon flux generated on the semiconductor chip is absorbed by phosphor particles. Converter 5; 18 may also be located outside the luminaire housing, e.g., the transducer functions may be performed by a transparent luminaire cover covered with phosphor particles.

Wavelength converter 5; 18 is constructed in such a way that the wavelengths of the spectral components of the LEDs and, in the case of multiple spectral components, the partial photon fluxes of each spectral component are most suitable for crop production. The plants may be exposed solely to the light generated by the proposed luminaires or combined with other sources. Various green plants such as lettuce, cucumbers, tomatoes, radishes, carrots, onions, cauliflowers, broccoli, green peas, wheat or barley greens, etc.

They have peculiarities of photosynthesis and morphogenesis and different development rates of individual plant organs (stems, leaves, roots, roots, flowers, fruits), so they may have individual needs for the composition of the light spectrum. In addition, the optimal composition of the light spectrum may vary at different stages of plant development.

Depending on the number of components and the range of their components, the proposed luminaires can be used in various plant lighting systems. For example, one-component far-red LEDs with full phosphorus conversion can be used in place of the same wavelength AlGaAs LEDs in plant matrix combinations combined with red and blue LEDs. Two-component partial or full conversion luminaires in the far red and blue spectrum can be used to grow plants by combining them in matrices with red lights or high pressure sodium lamps. Two-component full conversion LEDs in the far red and red spectral regions can be used in plant cultivation devices that are exclusively designed to meet photosynthetic and / or phytochrome-controlled photomorphogenetic needs, or in combination with blue LEDs. Finally, three-component phosphorus conversion luminaires, which radiate across all three spectral regions important to plant growth and development (far red, red, and blue), can be used in luminaires for universal plant cultivation that meet all photo physiological needs.

The average optimum composition of plant-satisfying light is such that the total photon flux contains about 75% red light, about 20% blue light, and about 5% far-red light. Therefore, it is proposed that the ratio of the partial fluxes of the widespread phosphor conversion LEDs with multiple spectral components to each component correspond to these proportions. For example, for luminaires that emit only the far red and blue light, the ratio of the respective partial fluxes would be 1: 4. For luminaires that emit only far-red and red-light, the ratio of the respective partial fluxes would be 1:15. For ternary components that emit far red, red, and blue light, the ratio of the respective partial fluxes would be 1: 15: 4.

There are several ways to determine the partial fluxes of each spectral component in the two and three spectral component luminaires for crop production. In the proposed luminaires, this is done by selecting the size and concentration of phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, the distance between the wavelength transducer and the electroluminescent structure and the position of the wavelength transducer inside or outside the luminaire housing.

The optimum spectrum of plant illumination can be achieved when the spectrum components of the illuminators are precisely matched to the optical absorption spectra of the phytopigments. In this case, the peak of the far red spectrum component of the proposed luminaires shall be matched to Pf_r form phytochrome absorption spectrum and correspond to approximately 730 nm. The peak of the additional red component of the spectrum should be consistent with the absorption spectrum of the chlorophylls and should correspond to approximately 660 nm. The peak of the additional blue component should be in agreement with the absorption spectra of carotenoids and cryptochromes and should correspond to approximately 450 nm. As the absorption spectral bands of the phytopigments are spread, the optimal wavelength values ​​given may differ within ± 20 nm.

Visually perceived color of previously offered LEDs is red (for single-component far-red and two-component red-far-red LEDs) or purple (for two-component blue-far-red and three-component red-blue-far-red LEDs). Strong light of this color can cause visual discomfort and color vision problems for glasshouse workers as well as people living near glasshouses. Therefore, in addition to the aforementioned three spectrum components (far red, red and blue), LEDs are additionally emitted in other areas of the spectrum. For example, their transducer may have additional phosphorus (not shown in Figures 1 and 2) radiating in a yellow, yellow-green, green or green-blue region. By selecting a partial flux of such auxiliary radiation, such LEDs can emit light that is perceived by the human vision as a light of some other color, such as white light with a defined correlated color temperature.

Phosphorus conversion luminaries for crop production are superior to the basic prototype [U.S. Patent No. 5,998,925 (1999)] and other white luminaires [U.S. Patent No. 6,084,250 (2000); 6,294,800 (2001); 6,501,102 (2002);

6,504,179 (2003) et al.] In that they generate a spectrum component with a peak in the far red region, which is necessary for Pf_r forms for excitation of phytochrome.

The proposed phosphorus conversion luminaires for crop production also have a number of advantages over known light sources whose radiation spectrum is optimized to meet the photophysiological needs of plants.

Phosphorus conversion luminaries for crop production are superior to previous analogs for fluorescent lamps for crop production [U.S. Pat. 3,287,586 (1963); 3,992,646 (1976); 4,371,810 (1983); 5,525,860 (1996); 7,259,509 (2007)], potentially higher throughput. For example, blue LEDs with 70% radiant power are technologically feasible [JM Phillips, ME Coltrin, MH Crawford, AJ Fischer, MR Krames,

R. Mueller-Mach, GO Mueller, Y. Ohno, LES Rohwer, JA Simmons, and JY Tsao, Laser & Photon. Rev. 1 (4), p. 307-333 (2007)]. Bearing in mind that converting blue (450 nm) light to far red (730 nm) light results in a much lower Stokes shift, the overall efficiency of producing far-red light in a given phosphor-conversion light can be up to 43%, almost twice the theoretical output. limit on fluorescent lamps (22%). Correspondingly, the efficiency of generating additional blue and red spectrum components is higher. Other advantages of phosphor conversion lamps with respect to fluorescent lamps include mechanical strength, small dimensions, longevity (up to 100,000 hours), fast switching, no sudden burnout, low power supply (2-4 V), compatibility with computer electronics, narrow band radiation absence of unwanted spectral components, hazardous substances (mercury) and flexibility in mounting into different matrices.

Phosphorus conversion luminaires for crop production are also superior to pure electroluminescent luminaires [U.S. Pat. 5,012,609 (1991)]. When the far red spectral component is generated in a single-component full conversion phosphor, the advantage of the InGaN semiconductor chip used in it is that, compared to the AlGaAs semiconductor used up to now, it has higher radiation efficiency, higher output temperature stability and higher corrosion resistance. When the far red spectral component is generated in a multicomponent partial or full conversion phosphor, electronic means of supplying a smaller number of channels can be used without this advantage. With the phosphorus conversion luminaire emitting in all three areas of the spectrum important for plant growth and development, apart from the above advantages, it is possible to evenly distribute the illumination of different spectral components with defined partial fluxes across plants, avoiding complex topologies for group lights.

FIG. 1 depicts the basic structure of a blue light partial conversion light for crop production. The LED contains a semiconductor chip 1, which generates blue light through injection electroluminescence. The chip is contained in a reflector cup 2 and connected to the terminals 3 by means of connected wires 4. The chip is covered by a wavelength transducer 5. The chip and the transducer are encapsulated in a transparent housing 6 such as a plastic or silicone die. Typically, a semiconductor chip is composed of a p-type layer connected to the anode terminals and an n-type layer connected to the cathode terminals which envelop the active layer. In the active layer, electrons injected from the n-type shell layer radially recombine with the holes injected from the p-type shell layer. A typical active layer material is triple In_xGai__xN alloy, where the thickness of the active layer and the molar fraction of the indium in the alloy x are chosen such that the emission band has a peak in the 400-500 nm spectrum.

The light generated in the semiconductor chip 1 passes through a wavelength transducer 5 containing the first type of phosphor particles 7 and may additionally contain a second type of phosphor particles 8 (Fig. 1 illustrates a case where both types of phosphor particles are used). The fate of photons emitted from a semiconductor chip can be twofold. The photon which in Fig. 1. marked by arrow 9, is not absorbed by phosphor particles and escapes from the chip into the environment through a transparent housing. The photon 10 is absorbed by the first type of phosphor particle 7 and converted to a photon 11 having a wavelength corresponding to a spectral component with a peak in the 700-760 nm (far red) spectrum. Meanwhile, photon 12 is absorbed by a second type of phosphor particle 8 and converted to photon 13, which has a wavelength in the 620-680nm (red) spectrum. Finally, the light emits light containing at least two spectral physiological components of the plant. A LED whose transducer 5 contains only the first type of phosphor particles 7 emits a two-component blue-far red light, and a LED whose transducer contains both types of phosphor particles 7 and 8 emits a three-component blue-red-far red light.

Fig. 2 illustrates the basic structure of a phosphorescent light for full conversion of close to UV light to phosphor. The illuminator contains a semiconductor chip 14 which generates dipped UV light by injection electroluminescence. The chip 14 is housed in a reflector cup 15 and connected to the terminals 16 using connected wires 17. The chip is covered by a wavelength transducer 18. The chip 14 and the transducer 18 are encapsulated in a transparent housing 19. Typically, a semiconductor chip is composed of a p-type layer connected to the anode terminals and a n-type layer connected to the cathode terminals which envelop the active layer. In the active layer, electrons injected from the n-type shell layer radially recombine with the holes injected from the p-type shell layer. A typical active layer material is either a GaN semiconductor compound or a triple In ^ Gai- ^ N or A? Gai ^ N alloy, or a quadruple In ^ -Al ^ Gai- ^ N alloy with the active layer thickness and the molar portion of the deposit x or the aluminum portion y are selected in the alloy such that the emission band has a peak at a wavelength shorter than 430 nm,

The light generated in the semiconductor chip 14 passes through a wavelength transducer 18 containing the first type of phosphor particles 21 and may additionally contain a second type of phosphor particles 24 and / or a third type of phosphor particles 27 (Fig. 2). case when three types of phosphor particles are used). All photons emitted from a semiconductor chip are absorbed by phosphor particles. The photon 20 is absorbed by the first type of phosphor particle 21 and converted to a photon 22 having a wavelength corresponding to a spectral component with a peak at 700-760 nm (far red). Photon 23 is absorbed by a second type of phosphor particle 24 and converted to photon 25 with a wavelength in the 620-680 nm (red) spectrum. Meanwhile, the photon

26th is absorbed by a third type of phosphor particle 27 and converted to a photon 28 with a wavelength in the 400-500 nm (blue) spectrum. Finally, the illuminator emits light that contains at least one component of the spectrum that is important for plant photo-physiology. The luminaire, whose transducer 18 contains only the first type of phosphor particles 21, emits only a distant red light; a lamp having a transducer having only the first type of phosphor particles 21 and the second type of phosphor particles 24 emits a two-component red-far red light; a luminaire having a transducer containing only phosphor particles 21 of the first type and 27 phosphor particles of the third type emits a two-component blue-beam red light; a LED whose transducer contains all three types of phosphor particles 21,24 and 27 emits a three-component blue-red-high-beam red light.

FIG. 3. Depicts the potential electroluminescence spectra of semiconductor chips offered for use in phosphorus conversion luminaires for crop production. For both partial and total conversion, the electroluminescence spectra of the LEDs must be consistent with the absorption spectra of the phosphorus. In addition, at partial conversion, the electroluminescence spectrum of the luminaire must be consistent with the photophysiological needs of the plants in the 400-500 nm spectral range.

FIG. 3 (a) depicts the electroluminescence spectrum corresponding to a semiconductor chip with an active layer made of triple In._AGai_._A.N alloy, whereby the thickness of the active layer and the molar fraction of the indium in the alloy are selected such that the peak at 450 nm in the blue spectral band. Such a chip can be used in a partial conversion scrub for crop production. FIG. 3 (b) depicts an electroluminescence spectrum corresponding to a semiconductor chip having an active layer made of triple In._xGai__xN alloy, where the thickness of the active layer and the molar fraction of the indium in the alloy are chosen such that the peak of the irradiance is at 380 nm in the near UV spectrum. Such a chip can be used in a full conversion light for crop production.

FIG. 4 depicts individual photoluminescence spectra corresponding to phosphores that could be used in phosphorus conversion luminaires for crop production. FIG. 4 (a) shows the photoluminescence spectrum corresponding to gadolinium and gallium oxide phosphorus activated by trivalent chromium ions [GdsGasO ^ Cr³¹) which absorbs blue or dipped UV light and emits a far red light with a spectral band at about 730 nm. Such phosphorus can be used in partial or full conversion luminaires for crop production to generate the far red component of the spectrum. Fig. 4 (b) shows a photoluminescence spectrum corresponding to nitridosilicate phosphorus activated by divalent europium ions [(Ca, Sr, Ba) 2Si5Ng: Eu], which absorbs blue or dipped UV light and emits red light with a spectral band at approximately peak. 660 nm. Such phosphorus can be used in partial or full conversion luminaires for crop production to generate a red spectral component. FIG. 4 (c) shows the photoluminescence spectrum corresponding to aluminate phosphorus activated by divalent europium ions (BaMgAlioOi7: Eu²⁺), which absorbs near-UV light and emits blue light with a spectral band at 450 nm. Such phosphorus can be used in crop conversion full-function luminaires to generate a blue spectral component.

FIG. 5 depicts the emission spectra of proposed partial conversion LEDs for crop production. All spectra have a blue component with a peak at 450 nm generated by an InGaN semiconductor chip due to injection electroluminescence and a far red spectrum component generated by a wavelength converter photoluminescence. The partial fluxes corresponding to the residual blue light and the light generated by each phosphor are determined by selecting the concentration of the phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, and the position of the wavelength transducer inside or outside the housing. Fig. 5 (a) depicts a spectrum corresponding to a two-component blue-to-far red light generated using partial blue light conversion Gd3Ga₅0i2: Cr in phosphor, which emits a far-red light through photoluminescence. The blue and distant red light partial photon fluxes are 80% and 20%, respectively. Such blue-far-red red lights can be used in composite lighting systems that have other sources that induce photosynthesis in chlorophylls, such as high-pressure sodium lamps. FIG. 5 (b) represents the spectrum corresponding to the three-component blue-red-beam red light, which is generated using partial conversion of the blue light generated by electroluminescence (Ca, Sr, Ba)₂Si5N₈: Eu ir

Gd3Ga50i₂: Cr³⁺ in phosphores, which emit red and far red light respectively, due to photoluminescence. The blue, red, and far red light partial photon fluxes are 20%, 75%, and 5%, respectively. Such blue-to-red-field red spotlights can be used for universal plant cultivation when all plant photophysiological needs are met.

FIG. 6 depicts the spectra of complete conversion LEDs offered for crop production. All of these LEDs, which have a semiconductor chip, · emit at least one component of longer waves due to phosphor photoluminescence, due to electroluminescent light generating wavelengths shorter than 430 nm. In multicomponent luminaires, partial photon fluxes corresponding to each phosphor are determined by selecting the concentration of phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, and the position of the wavelength transducer inside or outside the luminaire body. Fig. 6 (a) depicts a spectrum corresponding to a one-component far-red light that is generated by the complete conversion of the near-UV light to Gd3Ga50i₂: Cr^J'phosphor, which emits a far-red light through photoluminescence. Such a far red light can be used for plant growth in combination with other light sources that lack radiation at 730 nm. Fig.6 (b) depicts a spectrum corresponding to a two-component blue-to-far red light, which is generated using full-beam UV conversion BaMgAlioOn'Eu²¹ and Gd3Ga50i₂: Cr³⁺ in phosphores which emit blue and far red light due to photoluminescence. The blue and distant red light partial photon fluxes are 80% and 20%, respectively. Such blue-red illuminators can be used in composite lighting systems that have other sources that induce photosynthesis in chlorophylls, such as high-pressure sodium lamps. Fig. 6 (c) depicts a spectrum corresponding to a two-component red-to-far red light, which is generated using complete conversion of the near-UV light (Ca, Sr, Ba)₂Si₅N₈: Eu²⁺ and Gd₃Ga₅0i2: Cr³⁺ in phosphores which emit red and far red light due to photoluminescence. The red and far red light partial photon fluxes are 90% and 10%, respectively.

Such red-far-red LEDs can be used in plant cultivation equipment that is only adapted to meet photosynthetic and / or phytochrome-controlled photomorphogenetic needs. FIG. 6 (d) depicts a spectrum corresponding to a three-component blue-red-far-red light that is generated using full conversion of the near-UV light generated by electroluminescence BaMgAlioOp.'Eu, (Ca, Sr, Ba).₂Si₅Ns: Eu, and Gd3Ga₅0i2: Cr³⁺ phosphorus, which emits blue, red and far red light, respectively, due to photoluminescence. The blue, red, and far red light partial photon fluxes are 20%, 75%, and 5%, respectively. Such blue-red10 far-red luminaires can be used for universal plant cultivation when all plant photophysiological needs are met.