Double-side light-emitting up-conversion detector and preparation method and application thereof

Abstract

The invention discloses a double-side light-emitting up-conversion detector and a preparation method and application thereof, and belongs to the technical field of semiconductor devices. The up-conversion detector provided by the invention comprises a substrate, an anode layer, an A hole injection layer, a B hole injection layer, an A light-emitting layer, an electron transport layer, an infrared absorption layer, a hole transport layer, a B light-emitting layer, an electron injection layer and a cathode layer which are stacked, the light-emitting layer A and the light-emitting layer B are respectively and independently selected from at least one of CdSe-based quantum dots, CdS quantum dots, InAlAs / AlGaAs quantum dots and InP-based quantum dots; the hole injection layer A and the hole injection layer B are made of different materials. The up-conversion detector provided by the invention has the advantages of high resolution, low pixel crosstalk and long service life. The invention further provides a preparation method and application of the up-conversion detector.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a double-sided luminous up-conversion detector and a preparation method and application thereof. Background Art

[0002] Infrared (IR) upconversion devices are a type of optoelectronic devices that work in the infrared band and have the ability to convert incident infrared radiation into visible light or other detectable radiation. This conversion technology has broad application prospects in medical imaging, optical communications, infrared sensing and bioanalysis.

[0003] In recent years, the development of infrared upconversion devices has mainly relied on inorganic semiconductor materials (bulk materials) such as silicon and germanium. These devices usually achieve upconversion of infrared light to visible light through the emission and absorption of photogenerated carriers. Their main advantages include relatively low cost, mature manufacturing process, and stable operation under various environments.

[0004] However, existing infrared upconversion devices generally face the problem of resolution limitation. For example, the HAWAII-4RG infrared detector developed by Teledyne Imaging, even though it is the product with the highest pixel count on the market, has a pixel pitch of only 10μm or 15μm and a pixel count of only 4096×4096, which greatly limits its performance in high-resolution applications. In addition, since bulk materials are used as the light-emitting layer, these infrared upconversion devices often encounter pixel crosstalk problems if they want to achieve high-resolution imaging. In bulk materials, due to the long carrier diffusion length (greater than 10μm), if the resolution is too high, the mutual interference between adjacent pixels will seriously affect the image quality, limiting its application in high-resolution imaging.

[0005] In addition to up-conversion devices that use inorganic semiconductor materials as the light-emitting layer, there are also dual OLED light-emitting structures prepared with organic light-emitting layers. Although the conversion efficiency and luminous brightness of infrared-visible light are improved through structural optimization, there are still problems such as the organic light-emitting layer structure is easy to age, has a limited lifespan, and is not suitable for long-term use. At the same time, taking the existing dual OLED light-emitting layer infrared up-conversion devices as an example, the bulk materials such as DCJTB used in the organic light-emitting layer can only achieve low-resolution infrared detection imaging due to their large diffusion length (above 10μm). If the resolution is increased, pixel crosstalk is likely to occur, which greatly affects the imaging effect. In other words, the dual OLED light-emitting structure using organic materials, although the conversion efficiency and luminous brightness are high, still does not overcome the problems of low resolution and pixel crosstalk, and introduces a new problem of short life.

[0006] In summary, how to fully improve the resolution of infrared up-conversion devices while minimizing the pixel crosstalk phenomenon and extending the service life of the devices is a common problem faced by the new generation of up-conversion devices. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a double-sided luminous upconversion detector, which can effectively improve the resolution of the upconversion detector, reduce pixel crosstalk, and extend the service life.

[0008] The present invention also provides a method for preparing the double-side luminescent up-conversion detector.

[0009] The present invention also provides the application of the double-side luminescent up-conversion detector.

[0010] According to an embodiment of the first aspect of the present invention, there is provided a double-sided luminous up-conversion detector, the up-conversion detector comprising:

[0011] Substrate, anode layer, A hole injection layer, B hole injection layer, A light emitting layer, electron transport layer, infrared absorption layer, hole transport layer, B light emitting layer, electron injection layer and cathode layer;

[0012] The materials of the A light-emitting layer and the B light-emitting layer are independently selected from at least one of CdSe-based quantum dots, CdS quantum dots, InAlAs / AlGaAs quantum dots and InP-based quantum dots;

[0013] The A hole injection layer and the B hole injection layer are made of different materials.

[0014] The working mechanism of the upconversion detector is as follows: after the quantum dot infrared absorption layer absorbs infrared rays, hole-electrons are generated; the holes pass through the hole transport layer and undergo a hole-electron recombination reaction with the material in the B light-emitting layer to generate visible light; the electrons pass through the electron transport layer and undergo an electron-hole recombination reaction with the material in the A light-emitting layer to generate visible light.

[0015] The up-conversion detector according to the embodiment of the present invention has at least the following beneficial effects:

[0016] The double-sided luminescent upconversion detector provided by the present invention significantly improves the high resolution, photoelectron transmission efficiency and energy conversion efficiency of the upconversion detector through the selection and matching of structure and materials:

[0017] The present invention uses quantum dot material as the light-emitting layer. Since the diffusion length of the quantum dot material is only 100-200nm, theoretically high-resolution imaging with a pixel interval of only 200nm can be achieved, which greatly exceeds the limitations of traditional technology and achieves high resolution of infrared detectors.

[0018] Furthermore, the short diffusion length of the quantum dot material effectively reduces the pixel crosstalk problem in the horizontal direction, which means that each pixel can capture the light signal more accurately, improving the accuracy and quality of imaging and avoiding pixel crosstalk.

[0019] When CdSe quantum dots are selected as the material of the light-emitting layer, a wider display color gamut and longer display life can be obtained due to its high color conversion efficiency (>90%), high stability, and narrow luminescence spectrum. The use of quantum dot materials not only enhances the radiation stability of infrared up-conversion devices, but also ensures high performance in long-term use, meeting the needs of long-term operation.

[0020] At the same time, thanks to the flexible characteristics of quantum dot materials, the upconversion detector provided by the invention can be applied to a wider range of scenarios, including application fields that require flexible materials. Compared with traditional rare earth materials or their quantum dots, the quantum dot materials used in the luminescent layer of the present invention have lower costs and simpler preparation processes, and most importantly, have better luminescence performance and contrast.

[0021] Due to the dual-light-emitting layer design, after the infrared absorption layer receives near-infrared light irradiation, the generated electrons can be utilized by the A light-emitting layer, and the generated holes can be utilized by the B light-emitting layer, which greatly improves the utilization rate of photogenerated carriers, improves the PP conversion efficiency, and achieves more efficient photoelectron energy conversion. Different from traditional infrared up-conversion devices, the present invention can achieve higher visible light brightness under the same intensity of near-infrared light irradiation, further improving contrast and sensitivity.

[0022] In the up-conversion detector provided by the present invention, a double-layer hole injection layer is used to reduce the potential barrier gradient between different semiconductor materials, significantly improve the injection efficiency of carriers, and improve the conversion efficiency. Under the irradiation of near-infrared light of the same intensity, the up-conversion detector provided by the present invention has higher visible light brightness, further improving contrast and sensitivity.

[0023] According to some embodiments of the present invention, the substrate is selected from a flexible material or a rigid material. When a flexible material is selected, the up-conversion detector is used in a scene requiring flexibility, such as a wearable device.

[0024] According to some embodiments of the present invention, the flexible material includes at least one of an organic polymer or ultra-thin glass. The thickness of the ultra-thin glass is ≤ 0.2 mm.

[0025] According to some embodiments of the present invention, the rigid material includes at least one of a glass sheet, a quartz sheet, and a silicon sheet.

[0026] According to some embodiments of the present invention, the material of the anode layer includes at least one of In2O5Sn (indium tin oxide, referred to as ITO), IGZO, aluminum tin oxide and aluminum zinc oxide.

[0027] According to some embodiments of the present invention, the thickness of the anode layer is 100-300 nm, for example, 110-180 nm, more specifically, about 120 nm, 130 nm, 150 nm or about 160 nm.

[0028] According to some embodiments of the present invention, the anode layer has both transparency and conductivity.

[0029] According to some embodiments of the present invention, the materials of the A hole injection layer and the B hole injection layer are independently selected from at least one of PEDOT (poly (3,4-ethylenedioxythiophene), CAS: 155090-83-8), TFB (boron trifluoride, CAS: 220797-16-0), P3HT (CAS No.: 104934-50-1), PTAA (CAS: 1333317-99-9), TPD (CAS: 65181-78-4) and PCBM (CAS: 160848-22-6).

[0030] According to some embodiments of the present invention, the thickness of the hole injection layer A and the hole injection layer B are independently selected from any value in the range of 30 to 100 nm, for example, 40 to 60 nm, and more specifically, about 45 nm, 50 nm, 55 nm, 60 nm or about 65 nm.

[0031] According to some embodiments of the present invention, the CdSe-based quantum dots include CdSe / ZnS quantum dots, that is, they include a CdSe core and a ZnS shell wrapped around the surface of the CdSe core.

[0032] According to some embodiments of the present invention, the InP-based quantum dots include InP / ZnS quantum dots, that is, they include an InP core and a ZnS shell that wraps the surface of the InP core.

[0033] According to some embodiments of the present invention, the thickness of the A light-emitting layer and the B light-emitting layer are independently selected from any value in the range of 20 to 50 nm, for example, 25 to 40 nm, and more specifically, about 30 nm or about 35 nm.

[0034] According to some embodiments of the present invention, the material of the electron transport layer includes at least one of ZnO, TiO2 and Alq3.

[0035] According to some embodiments of the present invention, the thickness of the electron transport layer is 30 to 100 nm, for example, 50 to 90 nm, and more specifically, about 60 nm, 75 nm, or about 80 nm.

[0036] According to some embodiments of the present invention, the material of the infrared absorption layer includes PbS quantum dots.

[0037] According to some embodiments of the present invention, the infrared absorption layer has a thickness of 200-500 nm, for example, 300-450 nm, more specifically, about 350 nm or about 400 nm.

[0038] According to some embodiments of the present invention, the material of the hole transport layer includes at least one of TFB, P3HT and TPD.

[0039] According to some embodiments of the present invention, the thickness of the hole transport layer is 30-100 nm, for example, 50-90 nm, and more specifically, about 60 nm, 65 nm, 70 nm, 80 nm or about 85 nm.

[0040] According to some embodiments of the present invention, the material of the electron injection layer includes at least one of ZnO, TiO2 and Alq3 (8-hydroxyquinoline aluminum, CAS: 2085-33-8).

[0041] According to some embodiments of the present invention, the thickness of the electron injection layer is 30-100 nm, for example, 50-90 nm, and more specifically, about 70 nm, 75 nm, 80 nm or about 85 nm.

[0042] According to some embodiments of the present invention, the material of the cathode layer includes at least one of Au, Ag, Cu and Al.

[0043] According to some embodiments of the present invention, the thickness of the cathode layer is 100-300 nm, for example, about 150 nm, 200 nm or about 250 nm.

[0044] According to the above analysis, in the up-conversion detector provided by the present invention, there are many choices of materials for each layer. The combination of different quantum dots in the light-emitting layer and materials in other layers can provide optimized spectral characteristics and luminous efficiency for specific applications, thereby achieving higher equipment performance and application flexibility.

[0045] According to some embodiments of the present invention, the up-conversion detector is an infrared-visible up-conversion detector, which can realize the conversion of infrared light into visible light.

[0046] According to an embodiment of the second aspect of the present invention, a method for preparing the up-conversion detector is provided, the preparation method comprising sequentially arranging the anode layer, A hole injection layer, B hole injection layer, A light-emitting layer, electron transport layer, infrared absorption layer, hole transport layer, B light-emitting layer, electron injection layer and cathode layer on the substrate.

[0047] Since the preparation method of the upconverter adopts all the technical solutions of the upconverter of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment. Furthermore, the preparation method provided by the present invention is simple and easy to implement, and the step-by-step technology is industrially mature, so it is convenient for industrial promotion.

[0048] According to some embodiments of the present invention, the preparation method further comprises pre-treating the substrate before providing the anode layer. The pre-treating comprises at least one of grinding and polishing.

[0049] According to some embodiments of the present invention, the method for setting the anode layer includes forming and patterning performed in sequence. The forming method includes at least one of coating and magnetron sputtering. The patterning method includes at least one of laser marking or photolithography.

[0050] According to some embodiments of the present invention, the method for setting the A hole injection layer and the B hole injection layer includes at least one of spin coating and inkjet printing. Wherein, the A hole injection layer and the B hole injection layer are set, and the solvent of the slurry used is selected from at least one of water and toluene. The concentration of the slurry used is 5 to 25 mg / mL; for example, it can be about 10 mg / mL, 15 mg / mL or about 20 mg / mL. When the setting method is selected from the spin coating, heat treatment is required after the spin coating. The heat treatment temperature of the A hole injection layer is 100 to 120°C, for example, it can be about 110°C. The heat treatment time of the A hole injection layer is 10 to 30 minutes, for example, it can be about 20 minutes. The heat treatment temperature of the B hole injection layer is 120 to 150°C, for example, it can be about 130°C or about 140°C. The time of the B hole injection layer is 10 to 30 minutes; for example, it can be about 15 minutes.

[0051] According to some embodiments of the present invention, the setting methods of the A light-emitting layer and the B light-emitting layer are independently selected from at least one of inkjet printing, spin coating and atomic layer deposition. Wherein, the slurry of the A light-emitting layer or the B light-emitting layer is prepared, and the solvent is selected from toluene; and / or, the concentration is 1 to 10 mg / mL, for example, it can be about 5 mg / mL. When the setting method is selected from the spin coating, the setting method also includes heat treatment after the spin coating. The heat treatment of the A light-emitting layer is set at a temperature of 80 to 150°C; for example, it can be about 90°C, 100°C or about 120°C. The heat treatment of the A light-emitting layer is set for a duration of 5 to 40 minutes. For example, it can be about 20 minutes or about 30 minutes. The heat treatment of the B light-emitting layer is set at a temperature of 80 to 100°C, for example, it can be about 90°C. The heat treatment of the B light-emitting layer is set for a duration of 5 to 15 minutes. For example, it can be about 10 minutes.

[0052] According to some embodiments of the present invention, the method for providing the electron transport layer includes at least one of evaporation, atomic layer deposition and magnetron sputtering.

[0053] According to some embodiments of the present invention, the method for setting the infrared absorption layer includes at least one of spin coating, spray coating, inkjet printing and scraping. The slurry for setting the infrared absorption layer includes a solvent of n-octane; and / or a concentration of 30 to 80 mg / mL. For example, it can be about 50 mg / mL.

[0054] According to some embodiments of the present invention, the method for setting the hole transport layer comprises spin coating, wherein the solvent of the slurry used for setting the hole transport layer comprises toluene; and / or the concentration is 10 to 30 mg / mL; for example, it can be about 20 mg / mL.

[0055] According to some embodiments of the present invention, the method for providing the electron injection layer includes at least one of evaporation, spin coating, atomic layer deposition and magnetron sputtering.

[0056] According to some embodiments of the present invention, when the method for setting the electron injection layer includes the spin coating, the concentration of the slurry used is 250 to 350 mg / mL. For example, it can be about 300 mg / mL. The solvent used includes chloroform. It also includes heat treatment after the spin coating. The specific temperature is 200 to 300°C, for example, it can be about 250°C. The duration of the heat treatment is 5 to 15 minutes. For example, it can be about 10 minutes.

[0057] According to some embodiments of the present invention, the method for disposing the cathode layer includes evaporation.

[0058] According to some embodiments of the present invention, the preparation method further comprises packaging after the cathode layer is provided.

[0059] According to an embodiment of the third aspect of the present invention, there is provided an infrared-visible up-conversion imaging system, wherein the infrared-visible up-conversion imaging system comprises the up-conversion detector.

[0060] Since the infrared-visible upconversion imaging system adopts all the technical solutions of the upconversion detector of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, that is, it has a longer service life, higher resolution, energy conversion efficiency, and significantly avoids the pixel crosstalk problem.

[0061] According to some embodiments of the present invention, a readout circuit is integrated on the arrayed chip.

[0062] According to some embodiments of the present invention, there is an electrode on the arrayed chip, and the electrode is bonded to the cathode layer.

[0063] According to some embodiments of the present invention, the method for preparing the infrared-visible upconversion imaging system includes bonding the cathode layer to an electrode of the arrayed chip.

[0064] According to an embodiment of the fourth aspect of the present invention, there is provided an application of the up-conversion detector or the infrared-visible up-conversion imaging system in medical imaging, optical communication, infrared sensing and biological analysis.

[0065] Since the application adopts all the technical solutions of the up-conversion detector or the infrared-visible up-conversion imaging system of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments.

[0066] If there is no special explanation, the actual meaning of “about” in the present invention is that the error is allowed to be within the range of ±2%, for example, about 100 is actually 100±2%×100.

[0067] Unless otherwise specified, “between” in the present invention includes the number itself, for example, “between 2 and 3” includes the endpoint values ​​2 and 3.

[0068] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0070] Figure 1 It is a simplified flow chart of the test of energy conversion efficiency in the test example of the present invention;

[0071] Figure 2 It is a simplified flow chart of the test of energy conversion efficiency in the test example of the present invention. DETAILED DESCRIPTION

[0072] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0073] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0074] Example 1

[0075] In this example, a double-sided luminescent upconversion detector was prepared. The specific steps are as follows:

[0076] S1. Use ultra-thin glass (0.2 mm) made of flexible material as the substrate, remove impurities on the surface of the ultra-thin glass through processes such as grinding and polishing, and obtain a smooth substrate surface.

[0077] S2. Deposit a 150 nm thick conductive indium tin oxide (ITO) thin film on the substrate obtained in step S1 by magnetron sputtering to form an anode layer having both conductivity and transparency.

[0078] S3. Using a solution method (i.e., spin coating), a poly(3,4-ethylenedioxythiophene) (PEDOT) film is coated on the ITO anode layer to form a 50 nm thick A hole injection layer; wherein the solvent of the solution used is water with a concentration of 10 mg / mL; and then heat treated at 110°C for 10 min.

[0079] S4. Using a solution method, a boron trifluoride (TFB) material is coated (spin-coated) on the A hole injection layer to form a B hole injection layer with a thickness of 50 nm. The solvent of the solution used is toluene, and the concentration is 20 mg / mL. Then, heat treatment is performed at 150° C. for 10 min.

[0080] S5. Using a solution method, CdSe-based quantum dots (QDs, purchased from Suzhou Xingshuo Nanotechnology Co., Ltd., model CdSe / ZnS-625-100) were uniformly mixed in a toluene solvent to form a 5 mg / mL A light-emitting layer slurry, which was then used as a raw material to coat (spin coat) the B hole injection layer to form a 35 nm A light-emitting layer. The mixture was then heat treated at 90°C for 5 min.

[0081] S6. Using magnetron sputtering and other processes, a 75 nm thick zinc oxide (ZnO) film is deposited on the A light-emitting layer to serve as an electron transport layer.

[0082] S7. Using a solution method, lead sulfide (PbS) quantum dots (QDs, purchased from Suzhou Xingshuo Nanotechnology Co., Ltd., model number PbS-1050-100) material was uniformly dispersed in n-octane solvent to form an infrared absorption layer slurry with a concentration of 50 mg / mL, which was used as a raw material to coat the electron transport layer to form a 350 nm thick quantum dot infrared absorption layer.

[0083] S8. Using a solution method, the TFB material is coated on the quantum dot infrared absorption layer to form a 65 nm thick hole transport layer, wherein the solvent used in the solution is toluene with a concentration of 20 mg / mL.

[0084] S9. Referring to the method of step S5, a 35 nm B light-emitting layer is disposed on the surface of the hole transport layer.

[0085] S10. Using magnetron sputtering technology, a zinc oxide (ZnO) film is deposited on the B light-emitting layer as an electron injection layer with a thickness of 75 nm.

[0086] S11. A metal material such as aluminum (Al) is deposited on the electron injection layer by vapor deposition to form a topmost cathode layer with a thickness of 200 nm.

[0087] Example 2

[0088] In this example, a double-sided luminescent upconversion detector was prepared. The specific steps are as follows:

[0089] S1. Use flexible material ultra-thin glass (0.2 mm) as the substrate, clean and pre-treat it to ensure the surface is clean and smooth.

[0090] S2. On a clean ultra-thin glass substrate, a layer of transparent indium tin oxide (ln2O5Sn) is deposited by magnetron sputtering to form a 120nm thick anode layer.

[0091] S3. Spin coating the anode with PEDOT material to form a 60nm thick A hole injection layer, and perform appropriate heat treatment. The heat treatment condition is 110℃ / 20min to optimize the conductivity and transparency of the PEDOT layer. The solvent of the spin coating solution is water, and the concentration is 10mg / mL.

[0092] S4. Spin-coat P3HT material on the A hole injection layer to form a B hole injection layer with a thickness of 60 nm, and perform heat treatment to optimize its performance. The heat treatment condition is 140°C / 15min to improve the structural stability of the B hole injection layer. The solvent of the spin coating solution is toluene, and the concentration is 20 mg / mL.

[0093] S5. InP-based quantum dots (purchased from Suzhou Xingshuo Nanotechnology Co., Ltd., model InP / ZnS-560-50) were coated on the B hole injection layer by spin coating to form a 35nm thick A light-emitting layer, and then properly baked to improve its electron-hole recombination efficiency. The baking conditions were 120°C / 30min. The solvent of the slurry used for spin coating was toluene, and the slurry concentration was 5mg / mL.

[0094] S6. A 90 nm thick electron transport layer is formed by sputtering ZnO material on the A light emitting layer to improve the electron transport efficiency.

[0095] S7. Spin-coat the PbS quantum dot material on the electron transport layer to form a 450 nm thick quantum dot infrared absorption layer for efficiently absorbing infrared light. The solvent of the slurry used for spin coating is n-octane with a concentration of 50 mg / mL.

[0096] S8. Spin-coat the TFB material on the quantum dot infrared absorption layer to form a hole transport layer with a thickness of 80 nm to optimize the hole transport efficiency. The solvent of the slurry used for spin coating is toluene with a concentration of 20 mg / mL.

[0097] S9. CdS quantum dots (purchased from Beijing Biotech Biotechnology Co., Ltd., model: ABO-Cd-5-46) were coated on the hole transport layer by spin coating to form a 25 nm thick B light emitting layer to achieve efficient light emission. The concentration of the slurry used for spin coating was 5 mg / mL, and the solvent was toluene. Then, heat treatment was performed at 90°C for 5 min.

[0098] S10. Spin coating Alq3 material on the B light emitting layer to form a 90 nm thick electron injection layer to improve the electron injection efficiency. The concentration of the slurry used is 300 mg / mL, and the solvent used is chloroform. Then heat treatment is performed at 250°C for 10 minutes.

[0099] S11. Aluminum (Al) material is deposited on the electron injection layer by evaporation to form a 150 nm thick cathode, completing the preparation of the entire upconversion detector.

[0100] Comparative Example 1

[0101] This example prepares an up-conversion detector, which differs from Example 1 in that:

[0102] The A light-emitting layer and the B light-emitting layer of Example 1 are replaced with organic light-emitting materials (OLED); specifically, the A light-emitting layer is a doped light-emitting material CBP:Ir(ppy)2(acac), with a doping concentration of 8wt.% and a thickness of 30nm;

[0103] The B light-emitting layer is a doped light-emitting material CBP:Ir(ppy)2(acac) with a doping concentration of 8 wt.% and a thickness of 30 nm.

[0104] Comparative Example 2

[0105] This example prepares an up-conversion detector, which differs from Example 1 in that:

[0106] Steps S8 to S9 are not included.

[0107] Application Examples

[0108] In this example, an infrared-visible upconversion imaging system is prepared, which is specifically composed of the upconversion detector prepared in the embodiment or comparative example and an arrayed chip.

[0109] The arrayed chip is integrated with a readout circuit and provided with electrodes, and the electrodes are bonded to the cathode layer of the up-conversion detector.

[0110] Test Case

[0111] This example tests the lifespan, resolution, photoelectron transmission efficiency, energy conversion efficiency, luminescence performance, contrast, and pixel crosstalk of the up-conversion detectors obtained in the embodiments and comparative examples.

[0112] Test method: constant voltage (8V), constant infrared light (980nm, 5mW / cm 2 ) to test the luminous intensity decay curve of the up-conversion detector over time.

[0113] The results show that compared with the OLED light-emitting device of Comparative Example 1, the QLED structure provided by the present invention can achieve more stable and long-life light output due to the use of inorganic semiconductor materials as the light-emitting layer. The specific service life can reach 60,000 hours, while the life of the up-conversion detector of Comparative Example 1 is ≤30,000 hours.

[0114] Resolution and pixel crosstalk test method: constant voltage (8V), constant infrared light (980nm, 5mW / cm 2 ) to test the minimum luminescence resolution of the upconversion detector array chip.

[0115] The results show that compared with the diffusion length of the OLED in Comparative Example 1 and the inorganic semiconductor material in Comparative Example 2 (~10μm), the upconversion detector provided by the present invention has a shorter carrier diffusion length (<200nm), making it less likely for electrons to be generated from one detection pixel and run to another imaging pixel to emit light during the transmission process, making it more difficult to form pixel crosstalk.

[0116] Energy conversion efficiency test method: constant voltage (8V), constant infrared light (980nm, 5mW / cm 2 ), test the ratio of the number of photons emitted by the upconversion detector to the number of photons received. The specific test process is as follows Figures 1-2 As shown, the order of the up-conversion detectors was reversed (equivalent to the order of the A and B light-emitting layers), and the two-side tests were performed. The conversion efficiency = (the number of photons in the first test + the number of photons in the second test) / the number of photons from the infrared light source. The number of photons from the infrared light source is only the count of one irradiation.

[0117] The results show that compared with the single-sided light-emitting device of Comparative Example 3, the double-sided light-emitting device provided by the embodiment of the present invention can simultaneously utilize two photogenerated carriers (electrons and holes) for radiative recombination luminescence, so the photon conversion efficiency is theoretically twice that of the single-sided light-emitting device. It should be noted that the embodiments of the present invention are only a few options within the scope provided by the present invention, and do not represent the optimal choice. For example, the quantum dot types of the light-emitting layer and the quantum dot types of the infrared absorption layer may be recombined to obtain an upconversion detector with better performance.

[0118] In summary, the upconversion detector provided by the present invention can significantly improve its overall performance through structural design and material matching; it can be predicted that the infrared-visible upconversion imaging system including the above-mentioned upconversion detector also has excellent performance in terms of conversion efficiency and other aspects; the final upconversion detector and infrared-visible upconversion imaging system are expected to be widely used in medical imaging, optical communication, infrared sensing and biological analysis and other fields.

[0119] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A double-sided upconversion detector, It is characterized in that The up-conversion detector includes: Substrate, anode layer, A hole injection layer, B hole injection layer, A light emitting layer, electron transport layer, infrared absorption layer, hole transport layer, B light emitting layer, electron injection layer and cathode layer; The materials of the A light-emitting layer and the B light-emitting layer are independently selected from at least one of CdSe-based quantum dots, CdS quantum dots, InAlAs / AlGaAs quantum dots and InP-based quantum dots; The A hole injection layer and the B hole injection layer are made of different materials.

2. The up-conversion detector according to claim 1, It is characterized in that The thickness of the A light-emitting layer and the B light-emitting layer are independently selected from any value within the range of 20 to 50 nm.

3. The up-conversion detector according to claim 1, It is characterized in that The material of the infrared absorption layer includes PbS quantum dots; and / or the thickness of the infrared absorption layer is 200-500 nm.

4. The up-conversion detector according to claim 1, It is characterized in that The materials of the hole injection layer A and the hole injection layer B are independently selected from at least one of PEDOT, TFB, P3HT, PTAA, TPD and PCBM; and / or the thicknesses of the hole injection layer A and the hole injection layer B are independently selected from any value between 30 and 100 nm.

5. The up-conversion detector according to any one of claims 1 to 4, It is characterized in that The material of the electron transport layer includes ZnO, TiO 2 and at least one of Alq3; and / or, the thickness of the electron transport layer is 30 to 100 nm.

6. The up-conversion detector according to any one of claims 1 to 4, It is characterized in that The material of the hole transport layer includes at least one of TFB, P3HT and TPD; and / or the thickness of the hole transport layer is 30-100 nm.

7. The up-conversion detector according to any one of claims 1 to 4, It is characterized in that The electron injection layer includes ZnO, TiO 2 and at least one of Alq3; and / or, the thickness of the electron injection layer is 30 to 100 nm.

8. A method for preparing an up-conversion detector according to any one of claims 1 to 7, It is characterized in that The preparation method comprises sequentially arranging the anode layer, A hole injection layer, B hole injection layer, A luminescent layer, electron transport layer, infrared absorption layer, hole transport layer, B luminescent layer, electron injection layer and cathode layer on the substrate.

9. An infrared-visible upconversion imaging system, It is characterized in that The infrared-visible upconversion imaging system comprises the upconversion detector according to any one of claims 1 to 7; preferably, the infrared-visible upconversion imaging system further comprises an arrayed chip; preferably, the arrayed chip has electrodes, and the electrodes are bonded to the cathode layer.

10. Use of the up-conversion detector according to any one of claims 1 to 7 or the infrared-visible up-conversion imaging system according to claim 9 in medical imaging, optical communication, infrared sensing and biological analysis.

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