CN202268389U - Near-infrared diode using blue light chip to stimulate down-conversion phosphor - Google Patents

Abstract

The utility model relates to a near-infrared diode that uses a blue light chip to excite a down-conversion phosphor. The near-infrared diode includes a substrate, a blue-light chip, an infrared down-conversion light-emitting layer and/or a blue-light filter layer and a packaging layer matched therewith. The utility model adopts a GaInN blue light chip, which is non-toxic and pollution-free, and the down-converting fluorescent body adopted has a quantum conversion efficiency close to 200%. Under the excitation of blue light emitted by the blue light chip, the down-conversion infrared phosphor has high-efficiency infrared light emission, and the emitted near-infrared light has a wavelength of 900~1100nm and a center wavelength of 980nm. The near-infrared diode is environmentally friendly, easy for large-scale industrial production, low in cost, energy-saving and environmentally friendly, and can improve the luminous efficiency of the near-infrared diode, and has great potential in infrared remote control, infrared detection, optical fiber communication, environmental monitoring, biological imaging and biomedicine It has wide application prospects and can greatly expand the application market of Blu-ray chips.

Description

A near-infrared diode that uses a blue light chip to excite down-conversion phosphors

technical field

The utility model relates to a near-infrared diode device which uses a blue light chip to excite a "down-conversion" phosphor, and belongs to the technical field of light-emitting devices; communication, environmental monitoring, biological imaging and biomedicine and other fields. the

Background technique

Photoluminescence refers to the luminescence phenomenon caused by exciting luminous bodies with light. Light-emitting devices made of this phenomenon have been widely used in people's daily life. At present, it is found that the light conversion form of photoluminescence phenomenon mainly follows the following three rules: (1) A high-energy excitation photon causes a low-energy emission photon in the "Down-Shifting" form. (2) Two or more low-energy excitation photons cause an "up-conversion" (Up-Conversion) form of a high-energy emission photon. (3) A high-energy excitation photon causes two or more low-energy emission photons in the "down-conversion" (Down-Conversion) form. See the literature Advanced Materials, 2011, 23(22-23): 2675-2680. Generally, in the three conversions of photoluminescence, the conversion efficiency of Down-Shifting and Up-conversion are both less than 100%, and the conversion efficiency of Up-conversion is even lower. Currently, the quantum efficiency of the up-conversion phosphor with the highest conversion efficiency is less than 5%. This low-efficiency up-conversion phosphor has been coated on infrared chips to make red, green and blue light-emitting diode products. See "Solid Luminescent Materials", edited by Sun Jiayue et al., 2003, first edition, page 595, paragraph 1 description. However, due to the low light conversion efficiency of the phosphor, the luminous efficiency of this diode is extremely low, so that it is not competitive in practical applications. the

The quantum efficiency of the down-converting fluorescent powder is above 100%, which makes the down-converting fluorescent material have a potential application prospect in the field of light-emitting diodes. However, for a long time, the excitation light of the down-conversion phosphor is mostly in the vacuum ultraviolet (~180nm), and it is difficult for the actual chip to emit high-efficiency vacuum ultraviolet light. Therefore, this type of phosphor has never been practically applied in the field of light-emitting diodes. the

In recent years, due to the promotion of the silicon-based solar cell industry, as an effective way to improve the photoelectric conversion efficiency of silicon-based solar cells, down-conversion phosphors have become one of the research hotspots of photoluminescent materials. See the literature: Solar Energy Materials and Solar Cells , 2006, 90(9): 1189-1207; Solar Energy Materials and Solar Cells, 2007, 91(4): 238-249; J.Appl.Phys.2002, 92, 1668; Progress in Materials Science, 2010, 55 (5): 353-427. Recently, luminescent scholars have found that a kind of fluorescent powder co-doped with Yb ³⁺ rare earth has high-efficiency infrared light emission under the excitation of blue light, and its quantum efficiency is above 100%, and the highest can be close to 200%. Years of literature: Adv.Mater.2009, 21, 3073-3077; Appl.Phys.Lett., 2010, 96, 151106; Appl.Phys.Lett.2008, 92, 141112; Appl.Phys.Lett.2009, 94 , 061905; Appl.Phys.Lett.2007, 90, 061914; Journal of Applied Physics 2009, 106(6): 063518-063518-4; Solar Energy Materials and Solar Cells, 2007, 91(4): 238-249; Journal of Luminescence, 2011, 131(4): 608-613; Optics Letters, 2009, 34(22): 3565-3567; Phys.Rev.B, 2005, 71: 014119; Phys.Rev.B, 2010, 81 : 035107; Physical Review B, 2010, 81, 035107; Physical Review B 2010, 81, 155112. The above studies have found that this type of high-efficiency down-conversion fluorescent material has practical application value in improving the photoelectric conversion efficiency of silicon-based solar energy. The applicant of this patent believes that, considering that the down-conversion infrared phosphor has a conversion efficiency close to 200% under blue light excitation, it is feasible to prepare high-efficiency near-infrared diodes by using blue light chips to excite such phosphors. However, so far, there are no patents and literature reports on the application of this type of phosphors in the field of near-infrared diodes excited by blue light, and no data reports have proposed the idea of using down-conversion infrared phosphors excited by blue light to prepare near-infrared diodes.

Near-infrared diode is a very important light-emitting diode, which has a wide range of applications in infrared remote control, optical fiber communication, environmental monitoring, biological imaging and biomedicine. The current commercial near-infrared diode types are mainly organic electroluminescent diodes and GaAs semiconductor light-emitting diodes. However, organic light-emitting diodes have poor thermal stability and low luminous efficiency. However, GaAs diodes have a limited emission spectrum range, and the GaAs preparation process uses the element As. As a member of nitrogen group elements, As is a toxic element, arsenic compounds are highly toxic, and trivalent arsenic compounds are more toxic than other arsenic compounds. During the preparation or processing of As compounds, if they enter the human body and are absorbed, they can destroy the redox ability of cells, affect the normal metabolism of cells, cause tissue damage and body disorders, and directly lead to various diseases, including: high blood pressure , cardiovascular and cerebrovascular diseases, neuropathy, diabetes, abnormal skin pigmentation metabolism and skin keratosis, affect labor and living ability, and eventually develop into skin cancer, which may be accompanied by high incidence of bladder, kidney, liver and other visceral cancers. The latest research also shows that fetuses are more sensitive to arsenic toxicity than adults. It can be seen that the use of GaAs has great hidden dangers to the environment and endangers human health. Therefore, from an environmental point of view, it is necessary to find new environmentally friendly materials to replace GaAs products. the

At present, as the key technology in the field of fourth-generation solid-state lighting, blue light chips are an important component of white light diodes. White light-emitting diodes formed by coating yellow "down-transfer" phosphor YAG:Ce ³⁺ (the quantum efficiency of the phosphor is only close to 80%) with blue InGaN chips have developed rapidly since their appearance in 1996, and their luminous efficiency has been continuously improved. It is expected to replace Traditional lighting sources such as incandescent lamps, fluorescent lamps and high-pressure mercury lamps have become the most promising green lighting sources in the 21st century. Driven by the huge application market, the preparation technology of blue LED chips is becoming more and more mature, and the cost is decreasing year by year. At present, the price of GaN and GaAs diodes with the same power on the market is about 1/4 of the latter. Moreover, the nitrogen element in the InGaN of the blue-ray chip is not as toxic as the arsenic element, and the nitrogen resource is abundant and environmentally friendly.

Therefore, the utility model utilizes blue light chips to prepare near-infrared diodes, which has practical application value for improving luminous efficiency, reducing production costs, environmental protection and energy saving, and also expands the application market of blue light chips. the

Utility model content

The purpose of the utility model is to provide an environment-friendly near-infrared light-emitting diode device to improve the luminous efficiency of the near-infrared diode, reduce the cost, reduce environmental pollution, and at the same time, expand the application of the blue light chip. the

In order to achieve the above object, the utility model adopts the following technical solutions to achieve:

A near-infrared diode that uses a blue chip to excite down-conversion phosphors, including a bracket, a substrate on the bracket, a blue chip and a packaging layer on the substrate, and the substrate and the blue chip are connected through the packaging The wires of the layers are connected, and the near-infrared diode also includes an infrared down-conversion light-emitting layer arranged on the blue-light chip. the

Further, a blue light filter layer matched with the infrared down-conversion light-emitting layer is provided on the infrared down-conversion light-emitting layer. the

Preferably, the blue light filter layer is a flat filter or an arc filter with a concave surface facing the infrared down-conversion light-emitting layer. the

Preferably, the infrared down-conversion luminescent layer is a down-conversion phosphor coating coated on the blue chip or a down-conversion phosphor bulk layer provided on the blue chip. the

Preferably, the down-converting phosphor bulk layer disposed on the blue chip may be in direct contact with the blue chip, or a certain distance may be maintained between them, that is, there is a gap between them.

The substrate used in the utility model is a substrate used in the preparation process of a commercial blue-ray chip, which can be one of a sapphire substrate, a silicon substrate, a silicon carbide substrate, a gallium nitride substrate and an aluminum nitride substrate or more. the

Preferably, metal cooling fins are also provided on the support. the

The blue light chip used in the utility model is a GaInN chip, and the emission wavelength is 400-500nm. Preferably, the main emission peak is around 450nm, 470nm or 490nm, in order to more effectively excite the down-conversion phosphor. the

The process of preparing the blue light chip on the substrate adopts the existing blue light LED chip technology, preferably the epitaxial growth preparation technology. the

The infrared emission quantum efficiency of the near-infrared down-conversion phosphor layer used in the utility model under the excitation of blue light is greater than 100%, and the quantum conversion efficiency can be as high as nearly 200%. The purpose of using the down-converting phosphor with quantum efficiency greater than 100% is to improve the emission efficiency of infrared light. the

The emission wavelength of the down-conversion phosphor adopted in the utility model is 900-1100 nm, and the central wavelength is near 980 nm. The down-converting phosphor matrix materials used are preferably halides, oxides, sulfides, oxyhalides or oxysulfides. More preferably, the rare earth ions selected for the down-conversion phosphor matrix are rare earth ions co-doped with Yb ³⁺ , such as: using Pr ³⁺ -Yb ³⁺ , Er ³⁺ -Yb ³⁺ , Ho ³⁺ One or more of -Yb ³⁺ , Nd ³⁺ -Yb ³⁺ , Tm ³⁺ -Yb ³⁺ or Tb ³⁺ -Yb ³⁺ co-doped phosphors. The used blue light filter layer is a blue light filter that prevents blue light from passing through and allows infrared light to pass through.

The down-conversion phosphor layer used in the present invention can be a phosphor powder layer, or a fluorescent single crystal, fluorescent glass body, fluorescent transparent ceramic body, or phosphor powder embedded in an inorganic or organic glass body. the

The utility model utilizes the blue light chip to excite the near-infrared diode of the down-conversion phosphor, and the adopted down-conversion phosphor has high-intensity near-infrared light emission under the excitation of the blue light emitted by the GaInN blue light chip. the

The utility model utilizes the blue light chip to excite the near-infrared diode of the down-conversion phosphor, and after the blue-light filter is added on the infrared down-conversion light-emitting layer, the light emitted by the diode after power-on is infrared rays invisible to the naked eye, and the wavelength is in the 900-1100nm band. , Infrared rays with a center wavelength around 980nm. Without the blue light filter, the emitted light includes the visible blue light emitted by the chip and the invisible infrared light emitted by the down conversion phosphor. the

The near-infrared diode of the utility model, which utilizes the blue-light chip to excite the down-conversion phosphor, is environmentally friendly, easy for large-scale industrial production, low in cost, energy-saving and environment-friendly, and can improve the luminous efficiency of the near-infrared diode. The near-infrared diode has broad application prospects in infrared remote control, infrared detection, optical fiber communication, environmental monitoring, biological imaging and biomedicine, and can greatly expand the application market of blue light chips. the

Description of drawings

The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only used to illustrate the utility model and not to limit the protection scope of the utility model. the

FIG. 1 is a schematic structural diagram of the near-infrared LED in Example 1. The infrared phosphor is powder coating, and the blue light filter layer is not added to the structure of the LED. the

Fig. 2 is a schematic diagram of the structure of the near-infrared LED in Example 2, the infrared phosphor is powder coating, and a blue light filter is added to the structure of the LED. the

Fig. 3 is a schematic structural diagram of the near-infrared LED in Example 3, the infrared phosphor is a bulk layer, and no blue light filter layer is added to the structure of the LED. the

The structural representation of the near-infrared LED in Fig. 4 embodiment 4, the infrared phosphor is a block layer, and a blue light filter is added in the structure of the LED. the

Fig. 5 is a schematic diagram of a near-infrared diode with a certain distance between the blue light chip and the down-converting bulk phosphor, and using a curved filter. the

Fig. 6 is a schematic diagram of a commercial Blu-ray chip used in the utility model. the

Detailed ways

Example 1:

As shown in Figure 1, a near-infrared diode that uses a blue chip to excite a down-conversion phosphor includes a support 1, a substrate 2 on the support, a blue chip 3 and an encapsulation layer 4 prepared on the substrate, the substrate Both the bottom 2 and the blue light chip 3 are connected to the wire 7 passing through the encapsulation layer 4, and the near-infrared diode also includes an infrared down-conversion light-emitting layer 5 arranged on the blue-light chip 3, and the infrared down-conversion light-emitting layer 5 is coated on the blue light Down-converting phosphor coating on chip. Metal cooling fins 8 are also provided on the bracket. the

The preparation of the above-mentioned near-infrared diodes using the blue-light chip to excite the down-conversion phosphor is as follows: firstly, the prior art is used to prepare the blue-light LED chip. The center wavelength is preferably around 440-450nm, 460-470nm or 480-490nm, in order to more effectively excite the down conversion phosphor. Then use the existing white light LED technology to coat the down-conversion phosphor with a suitable thickness on the top of the blue-light chip. The infrared emission quantum efficiency of the down-conversion phosphor under the excitation of blue light is greater than 100%, the emission wavelength is 900-1100nm, and the center wavelength is at Around 980nm. The host material of the down conversion phosphor used is selected from halide, oxide, sulfide, oxyhalide or oxysulfide. The rare earth ions selected for the down-conversion phosphor matrix used are rare earth ions co-doped with Yb ³⁺ , such as: Pr ³⁺ -Yb ³⁺ , Er ³⁺ -Yb ³⁺ , Ho ³⁺ -Yb ³⁺ , Nd One or more of ³⁺ -Yb ³⁺ , Tm ³⁺ -Yb ³⁺ or Tb ³⁺ -Yb ³⁺ co-doped phosphors. The corresponding down-conversion phosphor has a quantum efficiency close to 200%. SrF ₂ : Yb ³⁺ , Pr ³⁺ ; Cs ₃ Y ₂ Br ₉ : Er ³⁺ -Yb ³⁺ ; CaF ₂ : Tb ³⁺ , Yb ³⁺ ; YPO ₄ : Yb ³⁺ , Tm ³⁺ ; GdAl ₃ (BO ₃ ) ₄ : RE ³⁺ , Yb ³⁺ , where RE=Pr, Tb or Tm; KPb ₂ Cl ₅ : Er ³⁺ , Yb ³⁺ ; GdBO ₃ : Tb ³⁺ , Yb ³⁺ ; YF ₃ : Pr ³⁺ , Yb ³⁺ ; YF ₃ : Nd ³⁺ , Yb ³⁺ ; NaYF ₄ : one or more of Pr ³⁺ , Yb ³⁺ . The above-mentioned phosphor powder can be replaced according to the needs, and the down-conversion infrared phosphor powder with high luminous efficiency, good chemical stability and low production cost can be preferentially selected. Finally, LED packaging technology is used for packaging.

After the above-packaged infrared diode is powered on, the light emitted contains the blue light emitted by the chip itself. the

Example 2:

As shown in Figure 2, a near-infrared diode that uses a blue chip to excite a down-conversion phosphor includes a support 1, a substrate 2 positioned on the support, a blue chip 3 prepared on the substrate and a resin encapsulation layer 4, the Both the substrate 2 and the blue light chip 3 are connected to the wire 7 that runs through the encapsulation layer 4, and the near-infrared diode also includes an infrared down-conversion light-emitting layer 5 disposed on the blue-light chip 3, and the infrared down-conversion light-emitting layer 5 is coated on the Down-converting phosphor coating on a blue chip. The infrared down-conversion luminescent layer 5 is also provided with a blue light filter layer 6 that matches the infrared down-conversion luminescent layer. The blue light filter layer 6 is an arc-shaped filter with a concave surface facing the infrared down-conversion luminescent layer. shape filter. the

The above-mentioned blue light filter layer 6 filters the remaining blue light after converting the phosphor powder under the excitation of blue light, and only obtains near-infrared light with a wavelength range of 900-1100 nm. The rest of the structure is the same as that of Embodiment 1 except that a blue light filter layer is added. the

After the above-packaged infrared LED diode is powered on, the light emitted does not contain the blue light emitted by the chip itself, and is expected to be applied to the current GaAs-related fields. the

Example 3:

As shown in Figure 3, a near-infrared diode that uses a blue chip to excite a down-conversion phosphor includes a support 1, a substrate 2 on the support, a blue chip 3 prepared on the substrate and a resin encapsulation layer 4, the Both the substrate 2 and the blue light chip 3 are connected to the wire 7 penetrating the encapsulation layer 4, and the near-infrared diode also includes an infrared down-conversion light-emitting layer 5 arranged on the blue-light chip 3, and the infrared down-conversion light-emitting layer 5 is arranged on the blue light A bulk layer of down-converting phosphors on top of the chip. the

The difference from Example 1 is that the phosphor is not a powder, but a block, which is one or more of a fluorescent single crystal, a fluorescent glass body, a fluorescent transparent ceramic body, and a block formed by embedding phosphor powder into an inorganic or organic glass body. form. The blue light chip of the near-infrared diode emits blue light, and the emitted blue light then excites the down-conversion fluorescent block to emit near-infrared light. The working principle is the same as that of embodiment 1. The blue light chip and the down-converting bulk phosphor can be in direct contact, or a certain distance can be kept. After the blue light chip and the down-converting fluorescent block are fixed, the existing LED packaging technology is used for packaging. the

After the infrared LED diode packaged above is energized, the light emitted contains the blue light emitted by the chip itself. the

Example 4:

As shown in Figure 4, a near-infrared diode that uses a blue chip to excite a down-conversion phosphor includes a support 1, a substrate 2 on the support, a blue chip 3 prepared on the substrate and a resin encapsulation layer 4, the Both the substrate 2 and the blue light chip 3 are connected to the wire 7 penetrating the encapsulation layer 4, and the near-infrared diode also includes an infrared down-conversion light-emitting layer 5 arranged on the blue-light chip 3, and the infrared down-conversion light-emitting layer 5 is arranged on the blue light A bulk layer of down-converting phosphors on top of the chip. The infrared down-conversion light-emitting layer 5 is also provided with a blue light filter layer 6 that matches the infrared down-conversion light-emitting layer. The blue light filter layer 6 adopts a flat filter, and the concave surface can be used to face the arc shape of the infrared down-conversion light-emitting layer. filter. the

The purpose of adding the blue light filter layer above is to filter out the remaining blue light after converting the phosphor under the excitation of blue light, and only obtain near-infrared light with a wavelength range of 900-1100nm. All the other structures are the same as in Embodiment 3. the

As shown in FIG. 5 , a certain distance is maintained between the blue chip and the down-conversion bulk phosphor, and a near-infrared diode with an arc filter is used. the

After the above-packaged infrared LED diode is powered on, the light emitted does not contain the blue light emitted by the chip itself, and is expected to replace GaAs chips in infrared remote control, infrared detection, optical fiber communication, environmental monitoring, biological imaging and biomedicine related fields. the

The commercial Blu-ray chips used in the foregoing embodiments 1 to 4 are shown in FIG. 6 . the

In summary, the 4 examples listed in Example 1 to Example 4 are only simple configurations of the utility model patent, and their structures are not limited to the listed shapes, and all within the conception of the utility model patent Any modifications, equivalent replacements and improvements, etc., should be included in the scope of protection of this new implementation model. the

Claims (7)

1. A near-infrared diode utilizing a blue chip to excite a down-conversion phosphor, comprising a support, a substrate positioned on a support, a blue chip and an encapsulation layer arranged on the substrate, and the substrate and the blue chip are all compatible with The wires penetrating through the encapsulation layer are connected, and the feature is that the near-infrared diode also includes an infrared down-conversion light-emitting layer arranged on the blue chip. 2. The near-infrared diode that utilizes a blue-ray chip to excite down-conversion phosphors as claimed in claim 1, wherein a blue-light filter layer that matches the infrared down-conversion light-emitting layer is also provided on the infrared down-conversion light-emitting layer . 3. The near-infrared diode that utilizes a blue-light chip to excite down-conversion phosphors according to claim 2, wherein the blue-light filter layer is a flat filter or an arc-shaped filter with a concave surface facing the infrared down-conversion luminescent layer. 4. The near-infrared diode utilizing a blue-light chip to excite a down-conversion phosphor as claimed in any one of claims 1-3, wherein the infrared down-conversion luminescent layer is a down-conversion phosphor coated on the blue-light chip Coating or down-converting fluorescent bulk layer on blue chip. 5 . The near-infrared diode for exciting down-conversion phosphors by using a blue-light chip according to claim 4 , wherein the down-conversion fluorescent bulk layer arranged on the blue-light chip is in direct contact with the blue-light chip. 6 . 6 . The near-infrared diode for exciting down-conversion phosphors by using a blue-light chip according to claim 4 , wherein there is a gap between the down-conversion fluorescent bulk layer arranged on the blue-light chip and the blue-light chip. 7 . 7. The near-infrared diode for exciting down-converting phosphors excited by a blue light chip according to any one of claims 1-3, wherein a metal heat sink is also provided on the bracket.

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