Dual-spectrum response photoelectric detection device

Abstract

This invention relates to the field of photoelectric detection technology, specifically to a dual-spectral response photoelectric detection device. It comprises, in sequence, a short-wavelength conversion layer, a transparent substrate layer, a conductive anode, a functional anode modification layer, a photosensitizing layer, a cathode buffer layer, and a metal cathode. The photosensitizing layer includes a mixing layer and a acceptor layer, with the mixing layer located near the functional anode modification layer and the acceptor layer near the cathode buffer layer. The short-wavelength conversion layer converts incident ultraviolet light into visible light that can pass through the transparent substrate layer and enter the photosensitizing layer. The functional anode modification layer converts near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitizing layer. The mixing layer absorbs the visible light converted by the short-wavelength conversion layer and the light converted by the functional anode modification layer, generating photoelectrons and photoholes. The photoelectrons are sequentially transported to the metal cathode via the acceptor layer and the cathode buffer layer, while the photoholes are transported to the conductive anode via the functional anode modification layer. This achieves a near-ultraviolet-near-infrared dual-spectral response.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detection technology, and specifically to a dual-spectral response photoelectric detection device. Background Technology

[0002] Photodetectors are sensors that convert incident light signals into electrical signals using the photoelectric effect of photosensitive materials. Their operation typically involves incident light absorption, photogenerated carrier generation and separation, and carrier collection. They are widely used in astronomical observation, environmental monitoring, spectral analysis, biomedical detection, optical communication, and wearable electronics. Traditional photodetectors are usually made of inorganic semiconductor materials such as Si and Ge. While they possess relatively mature photoelectric properties, their fabrication processes are relatively complex, production costs are high, and they have limitations in large-area fabrication, flexibility, and lightweight design.

[0003] Polymer materials, due to their excellent photosensitivity, light weight, low cost, and superior processing performance, have shown great application potential in the field of photoelectric detection. Photoelectric detectors based on polymer materials facilitate miniaturization, lightweighting, and low-cost fabrication, which can, to some extent, compensate for the shortcomings of traditional inorganic photoelectric detectors in terms of fabrication cost and processing technology. Furthermore, the wide variety of organic polymer semiconductor materials provides a rich selection of materials for photoelectric detectors. Polymer semiconductor materials with different photoelectric properties can be designed according to device requirements, making polymer photoelectric detectors of great research and application value in performance tuning and application expansion. They can be applied in fields such as astronomical observation, environmental monitoring, spectral analysis, and medical detection instruments. The photosensitizing layer of existing polymer photoelectric detectors typically adopts a bulk heterojunction structure formed by blending donor and acceptor materials, promoting the separation of photoexcitons through the interface between the donor and acceptor materials. Near-infrared photodetectors also have broad application prospects in wearable electronics, optical communication, and biomedical imaging.

[0004] However, existing polymer photodetectors still have shortcomings in the utilization of light in the near-ultraviolet and near-infrared bands, as well as in the separation and transport of photogenerated carriers. On the one hand, transparent substrates exhibit significant absorption or cutoff in certain ultraviolet bands, making it difficult for some ultraviolet light to penetrate the transparent substrate and reach the photosensitive layer, thus reducing the device's utilization rate of ultraviolet light. Simultaneously, ultraviolet irradiation may also cause photo-oxidative degradation of organic functional materials, affecting the device's operational stability and lifespan. On the other hand, the photon energy of some near-infrared light with wavelengths greater than 780 nm is lower than the band gap of commonly used organic semiconductor materials, or falls within a band where the photosensitive material has weak absorption capacity, making it difficult for the photosensitive layer to effectively absorb, resulting in low device responsivity in the near-infrared band. Furthermore, traditional bulk heterojunction photosensitive layers typically employ a single-layer structure blending donor and acceptor materials, making it difficult to precisely control their internal morphology and the distribution of donor and acceptor materials. To provide more donor-acceptor interfaces and promote exciton separation, existing photosensitive layers typically employ a high acceptor material content. However, a high acceptor material content can easily lead to problems such as acceptor material aggregation, increased non-radiative recombination losses, and difficulty in controlling phase separation states. It may also cause disorder in carrier transport paths, interfacial recombination losses, and increased dark current, affecting the photoelectric response performance and stability of the device.

[0005] Therefore, existing polymer photodetectors still struggle to simultaneously achieve effective responses in both the near-ultraviolet and near-infrared bands, as well as efficient separation and transport of photogenerated carriers. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a solution that effectively addresses the problems of insufficient light absorption in the ultraviolet band, low near-infrared responsivity, and low efficiency of photogenerated carrier separation and transport in the photosensitive layer of existing photodetectors, making it difficult to simultaneously achieve dual-spectral response and effective carrier collection.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a dual-spectral-response photodetector, wherein the photodetector has a short-wavelength conversion layer, a transparent substrate layer, a conductive anode, a functional anode modification layer, a photosensitive layer, a cathode buffer layer and a metal cathode arranged sequentially on the side where the short-wavelength conversion layer is located as the light incident side;

[0009] The photosensitizing layer includes a hybrid layer and a receptor layer, wherein the hybrid layer is located near the functional anode modified layer and the receptor layer is located near the cathode buffer layer;

[0010] The short-wavelength conversion layer is used to convert incident ultraviolet light into visible light that can pass through the transparent substrate layer and enter the photosensitive layer. The functional anode modification layer is used to convert near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitive layer. The mixing layer is used to absorb the visible light converted by the short-wavelength conversion layer and the light converted by the functional anode modification layer, respectively, and generate photogenerated electrons and photogenerated holes. The photogenerated electrons are transported to the metal cathode sequentially through the acceptor layer and the cathode buffer layer, and the photogenerated holes are transported to the conductive anode through the functional anode modification layer.

[0011] Furthermore, the material of the short-wavelength conversion layer includes one or more of the following: TiO2-based materials, silicon-rich oxide systems, SiOx, or liquid crystal polymer materials containing azobenzene photosensitive units.

[0012] Furthermore, the functional anode modification layer includes a hole transport host material and an infrared light conversion material doped therein;

[0013] The infrared light conversion material is used to convert near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitive layer.

[0014] The hole transport host material is used to transport the photogenerated holes to the conductive anode.

[0015] Furthermore, the hole transport host material includes any one or more of the following: inorganic metal oxides with high work function, small organic molecules with low highest occupied molecular orbital energy levels, or organic conductive polymers.

[0016] The infrared light conversion material includes any one or more of the following: rare earth ion-doped upconversion nanoparticles, transition metal ion-doped compounds, organic infrared photosensitive dyes, lead sulfide quantum dots, thiophene-based conjugated polymers, or phthalocyanine dyes.

[0017] Furthermore, the infrared light conversion material in the functional anode modification layer has a doping mass fraction of 0.1 wt% to 10 wt%, with the remainder being the hole transport host material.

[0018] Furthermore, the hybrid layer is composed of a donor material and a macromolecular polymer;

[0019] The donor material includes one or more of PBDTTT-EFT, PTB7, PPDT2FBT, P3HT and PM6;

[0020] The macromolecular polymer material is a naphthalimide-based polymer, including one or more of PNDI2OD-T2, NDI-fused thiophene copolymer, and P(IDT-NDI).

[0021] Furthermore, the thickness of the hybrid layer is 0.8~2 µm.

[0022] Furthermore, the doping amount of the macromolecular polymer material is 1% to 10%.

[0023] Furthermore, the material of the receptor layer includes any one or more of fullerene derivatives, perylene diimide derivatives, or naphthalene diimide derivatives.

[0024] Furthermore, the transparent substrate is made of any one or more of glass, transparent polymer flexible materials, or biodegradable materials.

[0025] Furthermore, the conductive anode material is any one or more of indium tin oxide (ITO), conductive polymer poly(3,4-ethylenedioxythiophene / polystyrene sulfonate) (PEDOT:PSS), graphene, and carbon nanotubes.

[0026] Furthermore, the cathode buffer layer material is an inorganic compound with a low work function or an organic compound with a high lowest unoccupied level (LUMO). The inorganic compounds include cesium carbonate (Cs2CO3), lithium fluoride (LiF), and calcium oxide (CaO). The organic compounds are o-phenanthroline compounds, including 2,9-dimethyl-4,7-biphenyl-1,10-o-diaphenanthrene (BCP) and 4,7-biphenyl-1,10-o-diaphenanthrene (BPhen). The oxadiazole electron transport materials are 2-(4-diphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and 1,3-bis[(4-triamine-butylphenyl)-1,3,4-diazoamino-5-yl]benzene (OXD-7). The imidazole compounds are 1,3,5-tris(N-phenyl-benzimidazole-2)benzene (TPBi).

[0027] Furthermore, the material of the metal cathode layer is a metal thin film or an alloy thin film, which may be a lithium, magnesium, calcium, strontium, aluminum, indium, or other metal thin films, or alloy thin films of them with copper, gold, silver, etc.

[0028] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0029] 1. This invention forms a synergistic pathway by combining a short-wavelength conversion layer, a functional anode modification layer, and a photosensitive layer composed of a hybrid layer and a acceptor layer. This pathway involves the spectral modulation of incident light, the absorption of light in the corresponding wavelength band by the photosensitive layer, the generation and separation of photogenerated carriers, and the selective transport and collection of carriers. As a result, a dual-band response to the near-ultraviolet and near-infrared bands can be formed in a single device.

[0030] 2. The present invention converts a portion of the ultraviolet light with low transmittance of the transparent substrate layer into visible light that can pass through the transparent substrate layer and be absorbed by the hybrid layer through a short-wave conversion layer. This facilitates at least a portion of the converted light to enter the photosensitive layer and participate in the photoelectric response. At the same time, the absorption and conversion of ultraviolet light by the short-wave conversion layer helps to reduce the amount of ultraviolet light reaching the organic functional layer and reduce the risk of degradation of organic functional materials caused by ultraviolet irradiation.

[0031] 3. This invention uses near-infrared light functional materials in the functional anode modification layer to absorb, sensitize, or convert the wavelength of near-infrared light, so that the near-infrared light energy can participate in the photoelectric response of the device. It also provides a hole transport channel between the hybrid layer and the conductive anode through the hole transport host material, so that the layer has both near-infrared spectral modulation and anode-side hole transport functions.

[0032] 4. The present invention uses a polymer acceptor mass percentage of 1% to 10% in the hybrid layer, which helps to reduce the possibility of excessive aggregation when the acceptor content is too high; the thickness of the hybrid layer is set to 0.8 μm to 2 μm, which helps to increase the propagation distance of incident light in the hybrid layer and improve its absorption probability of photons in the absorption edge band; the independently set acceptor layer is used to receive photogenerated electrons from the hybrid layer and transport them to the cathode side, so that light absorption, exciton dissociation at the acceptor interface and electron transport each have corresponding structural carriers.

[0033] 5. In this invention, a cathode buffer layer is disposed between the acceptor layer and the metal cathode. Based on the characteristics of the selected buffer material, it is used to adjust the interface between the acceptor layer and the metal cathode and assist in the extraction of photogenerated electrons to the metal cathode. When the cathode buffer layer is made of an organic material with electron transport and hole blocking functions, it can also suppress the migration of holes to the metal cathode, thereby forming an electron selective collection side together with the acceptor layer. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a dual-spectral response photodetector device according to the present invention;

[0036] Figure 2 The image shows the response spectrum of the device in Embodiment 1 of the present invention under AM1.5 illumination.

[0037] Figure 3The image shows the response spectrum of the device in Embodiment 2 of the present invention under AM1.5 illumination.

[0038] Figure 4 This is an absorption diagram of the photosensitive layer material in Embodiment 3 of the present invention;

[0039] Figure 5 The image shows the response spectrum of the device in Embodiment 4 of the present invention under AM1.5 illumination.

[0040] Figure 6 The image shows the response spectrum of the device in Embodiment 5 of the present invention under AM1.5 illumination.

[0041] Figure 7 This is a simulation diagram of the optical field distribution of the device in Embodiment 6 of the present invention;

[0042] Figure 8 This is a diagram showing the optical path relationship of naturally incident light in the detector device of this invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0044] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail. The terms “comprising,” “including,” “having,” “containing,” etc., as used herein are open-ended terms, meaning that they include but are not limited to. Unless the context clearly indicates otherwise, the expressions “a” and “an” as used herein include plural references. It should be noted that “first,” “second,” etc., are used merely for convenience of description and distinction and should not be construed as indicating or implying relative importance. The term “about” as used herein indicates a range of ±20% of the following numerical value. In some embodiments, the term “about” indicates a range of ±10% of the following numerical value. In some embodiments, the term “about” indicates a range of ±5% of the following numerical value. The invention is further described below with reference to embodiments.

[0045] This invention provides a broad-spectral-response organic detection device, such as... Figure 1As shown, the device structure comprises, in sequence, a short-wavelength conversion layer 1, a substrate layer 2, a conductive anode 3, a functional anode modification layer 4, a hybrid layer 5, an acceptor layer 6, a cathode buffer layer 7, and a metal cathode 8. The photosensitive layer includes a hybrid layer and an acceptor layer, with the hybrid layer located near the functional anode modification layer and the acceptor layer near the cathode buffer layer. The short-wavelength conversion layer converts incident ultraviolet light into visible light that can pass through the transparent substrate layer and enter the photosensitive layer. The functional anode modification layer converts near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitive layer. The hybrid layer absorbs the visible light converted by the short-wavelength conversion layer and the light converted by the functional anode modification layer, respectively, and generates photoelectrons and photoholes. The photoelectrons are transported sequentially through the acceptor layer and the cathode buffer layer to the metal cathode, while the photoholes are transported through the functional anode modification layer to the conductive anode.

[0046] The short-wavelength conversion layer is composed of an ultraviolet light conversion film, which is used to convert ultraviolet light that cannot be transmitted through the substrate into long-wavelength visible light, thereby enhancing the utilization rate of short-wavelength light by the photosensitive layer.

[0047] The functional anode modification layer consists of a hole transport host material and an infrared light conversion material doped therein, which is used to broaden the spectral response range of the device and optimize the hole injection efficiency.

[0048] The photosensor layer is a bilayer functional stacked structure, comprising a hybrid layer and an acceptor layer. The hybrid layer is a thick film with a thickness of 0.8–2 μm, significantly greater than the thickness of other auxiliary functional layers in the device and also significantly greater than the conventional thickness of the photosensor layer in traditional polymer photovoltaic devices (typically 100–300 nm). The hybrid layer is composed of a blend of donor material and a lightly doped macromolecular polymer acceptor material, while the acceptor layer is composed of an electron-selective transport material. The bulk heterojunction structure, through the blending of donor and acceptor materials, broadens the absorption band and increases exciton generation sites. Simultaneously, the thick film morphology extends the photon propagation path at the absorption edge, enhancing light capture efficiency. The bulk heterojunction structure is a core active layer structure in organic photovoltaic devices, formed by three-dimensional interpenetrating blending of donor and acceptor materials at the nanoscale, creating a bulk network structure with a large-area donor / acceptor interface.

[0049] It should be noted that the short-wavelength conversion layer, the functional anode modification layer, and the photosensitizing layer composed of a hybrid layer and an acceptor layer of the present invention work together to form a triple-layered spectral utilization and carrier management mechanism. For example... Figure 8The diagram shows the optical path of naturally incident light in the detector device of this invention. When natural light is incident from the side where the short-wavelength conversion layer is located, the incident ultraviolet light is converted into visible light that can pass through the transparent substrate layer and is absorbed by the hybrid layer. After the incident near-infrared light reaches the functional anode modification layer, it is converted into light within the absorbable wavelength range of the hybrid layer by the infrared light conversion material therein. The short-wavelength conversion layer and the functional anode modification layer thus convert ultraviolet light and near-infrared light respectively. The converted light enters the hybrid layer and is absorbed, thereby generating excitons. The donor material and the polymer acceptor material inside the hybrid layer form a donor / acceptor interface to promote exciton dissociation and generate photogenerated electrons and photogenerated holes.

[0050] The hybrid layer of this invention employs a thick film structure of 0.8–2 μm to increase the propagation distance of light within the layer and improve the absorption probability of photons in the absorption edge band. An independently configured acceptor layer is used for selective transport of photogenerated electrons. The dissociated photogenerated electrons are transported sequentially through the acceptor layer and the cathode buffer layer to the metal cathode, while photogenerated holes are transported along the donor phase and through the functional anode modification layer to the conductive anode. Therefore, the short-wavelength conversion layer and the functional anode modification layer constitute the conversion paths for ultraviolet and near-infrared light, respectively. The double-layered photosensitive layer receives the converted light and completes light absorption, exciton dissociation, and carrier transport, thereby forming a synergistic path from light conversion of different wavelengths to charge collection. This broadens the spectral response range of the device, improves light utilization efficiency, reduces dark current, and enhances the stability of the photosensitive layer.

[0051] Example 1:

[0052] This embodiment provides a method for fabricating a broad-spectrum-response organic detection device, as detailed below:

[0053] Step 1: Clean the substrate consisting of a glass substrate and a conductive anode ITO, and then dry it with nitrogen gas; spin-coat the TiO2 precursor solution on the lower surface of the substrate (i.e., the backlight side) at a spin speed of 2000 rpm for 30 seconds, and then anneal it to form a short-wave conversion layer.

[0054] Step 2: Molybdenum trioxide (MoO3) with a thickness of 10 nm is prepared on the surface of transparent conductive anode ITO by thermal evaporation. PbS quantum dots (with a particle size of about 5 nm and a doping mass fraction of 5 wt%) are deposited on the surface of MoO3 by spin coating to form a functional anode modification layer.

[0055] Step 3: Using spin coating, the donor material PBDTTT-EFT and the low-doped macromolecular polymer PNDI2OD-T2 were mixed at a mass ratio of 1:1 (i.e., doping content of 50 wt%) on the functional anode modification layer. The mixture was then dissolved in chlorobenzene solvent to form a mixed solution with a concentration of 20 mg / mL. In a nitrogen glove box, the mixed solution was spin-coated onto the functional anode modification layer at a speed of 800 rpm until the film dried. Subsequently, it was annealed at 90°C for 5 minutes to obtain a mixed layer with a thickness of approximately 800 nm.

[0056] Step 4: Dissolve the receptor material [6,6]-phenyl-C61-butyrate methyl ester (PCBM) in chlorobenzene to obtain a receptor solution with a concentration of 20 mg / mL. Spin-coat the receptor solution onto the above mixed layer at a speed of 2000 rpm for 40 seconds, and then anneal at 70°C for 3 minutes to obtain a receptor layer with a thickness of about 20 nm. The mixed layer and the receptor layer together constitute the photosensitizing layer of the present invention.

[0057] Step 5: Evaporate a 10 nm cathode buffer layer Bphen on the surface of the photosensitive layer, and then evaporate a 100 nm metal cathode Ag on the cathode buffer layer to obtain the photodetector device of the present invention.

[0058] The photovoltaic performance of the photoelectric detector device prepared in this embodiment was tested using a xenon lamp to simulate a solar source (AM1.5G, 100 mW / cm²). 2 The test results are as follows: Figure 2 As shown, the prepared photoelectric detector responds across the entire wavelength band, but the spectrum lacks specificity for detection.

[0059] Example 2:

[0060] The difference between this embodiment and Embodiment 1 lies in the ratio of the donor material to the macromolecular polymer during the preparation of the mixed layer in step 3. Specifically:

[0061] The donor material PBDTTT-EFT and the low-doped macromolecular polymer PNDI2OD-T2 were prepared by spin coating on the functional anode modification layer at a mass ratio of 95:5 (i.e., doping content of 5 wt%) and dissolved in chlorobenzene solvent to form a mixed solution with a concentration of 23 mg / mL. In a nitrogen glove box, the mixed solution was spin coated on the functional anode modification layer at a speed of 800 rpm until the film dried. Then, it was annealed at 90°C for 5 minutes to obtain a mixed layer with a thickness of about 800 nm. The structure and preparation parameters of the remaining layers were the same as in Example 1.

[0062] Photovoltaic testing was performed on the photodetector device prepared in this embodiment. Figure 3The image shows the response spectrum of the device under AM 1.5G illumination. It can be seen that, unlike Example 1, the detector device prepared in this example achieves a dual-spectral response of short-wavelength and near-infrared narrowband.

[0063] Example 3:

[0064] The difference between this embodiment and Example 1 lies in steps 3 and 4 for preparing the photosensitizing layer: PTB7 is used as the donor material in the mixed layer of the photosensitizing layer, and the PNDI2OD-T2 doping content is 8 wt%; the donor concentration is 52 mg / mL, the solvent is a chlorobenzene / 1,8-diiodooctane mixed solvent (volume ratio 97:3), the spin coating speed is 700 rpm, the spin coating time is 120 seconds, and the thickness of the mixed layer is about 1 μm; the structure and preparation parameters of the remaining layers are the same as in Example 1; under zero bias illumination, the responsivity of the photodetector at a wavelength of 760 nm is measured to be 110 mA / W. Figure 4 This is the absorption diagram of the photosensitive layer material provided by the present invention.

[0065] Example 4:

[0066] The difference between this embodiment and Embodiment 1 lies in the materials of the functional anode modification layer and the hybrid layer:

[0067] In step 2, PCPDTBT and PTAA are mixed at a mass ratio of 5:95 and dissolved in chlorobenzene, with a total concentration of 5 mg / mL. The ITO conductive glass substrate is treated with UV-ozone for 15 minutes to improve surface wettability. Then, in a nitrogen glove box, the mixed solution is spin-coated onto the ITO anode at a speed of 3000-4000 rpm for 30 seconds, and annealed at 100°C for 10-15 minutes to obtain the functional anode modification layer.

[0068] In step 3, the donor material PBDTTT-EFT and the low-doped macromolecular polymer PNNTH were prepared by spin-coating onto the functional anode modification layer at a mass ratio of 90:10 (i.e., doping content of 10 wt%), dissolved in chlorobenzene solvent at a concentration of 18 mg / mL. In a nitrogen glove box, the mixed solution was spin-coated onto the functional anode modification layer at 600 rpm until the film dried, and then annealed at 90°C for 5 minutes to obtain a mixed layer with a thickness of approximately 1.2 μm.

[0069] A xenon lamp was used to simulate the sunlight (AM 1.5G, 100 mW / cm²). 2 The test results are as follows: Figure 5 As shown, the prepared photodetector device has a response in the shortwave and near-infrared bands.

[0070] Example 5:

[0071] The difference between this embodiment and embodiment 4 is that:

[0072] In step 3, the donor material PBDTTT-EFT and the low-doped macromolecular polymer PNNTH were spin-coated onto the functional anode modification layer at a mass ratio of 90:10 (i.e., a doping content of 10 wt%), dissolved in chlorobenzene solvent at a concentration of 6 mg / mL. The mixture was spin-coated at 800 rpm for 60 s in a nitrogen glove box, followed by annealing at 90°C for 5 minutes to obtain a mixed layer with a film thickness of approximately 200 nm.

[0073] A xenon lamp was used to simulate the sunlight (AM 1.5G, 100 mW / cm²). 2 The test results are as follows: Figure 6 As shown, the prepared photodetector has a response over a wide spectral range, but cannot achieve light detection in a specific wavelength band.

[0074] Example 6:

[0075] The difference between this embodiment and Example 1 is as follows: In the mixed layer of the photosensitizing layer, P3HT is used as the donor material, with a PNDI2OD-T2 doping content of 3 wt%; the donor concentration is 60 mg / mL, the solvent is chlorobenzene, the spin coating speed is 600 rpm, the spin coating time is 90 seconds, and the mixed layer thickness is approximately 800 nm; the acceptor layer is C60, prepared by vacuum evaporation, with a thickness of 15 nm; the annealing temperature of the mixed layer is adjusted to 110℃, and the annealing time is 10 minutes. The structure and preparation parameters of the remaining layers are the same as in Example 1.

[0076] Photovoltaic testing was performed on the photodetector device prepared in this embodiment. Figure 7 By simulating the optical field response of optoelectronic devices, it can be seen that light in the short-wavelength band and the long-wavelength band at the absorption edge has an optical field intensity in the device, thereby realizing exciton collection and response in this band.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-spectral response photodetector, characterized in that, The photodetector device has a short-wavelength conversion layer, a transparent substrate layer, a conductive anode, a functional anode modification layer, a photosensitive layer, a cathode buffer layer, and a metal cathode arranged sequentially on the side where the short-wavelength conversion layer is located. The photosensitizing layer includes a hybrid layer and a receptor layer, wherein the hybrid layer is located near the functional anode modified layer and the receptor layer is located near the cathode buffer layer; The short-wavelength conversion layer is used to convert incident ultraviolet light into visible light that can pass through the transparent substrate layer and enter the photosensitive layer. The functional anode modification layer is used to convert near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitive layer. The mixing layer is used to absorb the visible light converted by the short-wavelength conversion layer and the light converted by the functional anode modification layer, respectively, and generate photogenerated electrons and photogenerated holes. The photogenerated electrons are transported to the metal cathode sequentially through the acceptor layer and the cathode buffer layer, and the photogenerated holes are transported to the conductive anode through the functional anode modification layer.

2. The dual-spectral response photodetector according to claim 1, characterized in that, The material of the short-wavelength conversion layer includes one or more of the following: TiO2-based materials, silicon-rich oxide systems, SiOx, or liquid crystal polymer materials containing azobenzene photosensitive units.

3. The dual-spectral response photodetector according to claim 1, characterized in that, The functional anode modification layer includes a hole transport host material and an infrared light conversion material doped therein; The infrared light conversion material is used to convert near-infrared light in the incident light into light within the absorbable wavelength range of the photosensitive layer. The hole transport host material is used to transport the photogenerated holes to the conductive anode.

4. A dual-spectral response photodetector according to claim 3, characterized in that, The hole transport host material includes any one or more of the following: inorganic metal oxides with high work function, small organic molecules with low highest occupied molecular orbital energy levels, or organic conductive polymers. The infrared light conversion material includes any one or more of the following: rare earth ion-doped upconversion nanoparticles, transition metal ion-doped compounds, organic infrared photosensitive dyes, lead sulfide quantum dots, thiophene-based conjugated polymers, or phthalocyanine dyes.

5. A dual-spectral response photodetector according to claim 3 or 4, characterized in that, The infrared light conversion material in the functional anode modification layer has a doping mass fraction of 0.1 wt% to 10 wt%, with the remainder being the hole transport host material.

6. A dual-spectral response photodetector according to claim 1, characterized in that, The hybrid layer is composed of a donor material and a macromolecular polymer; The donor material includes one or more of PBDTTT-EFT, PTB7, PPDT2FBT, P3HT and PM6; The macromolecular polymer material is a naphthalimide-based polymer, including one or more of PNDI2OD-T2, NDI-fused thiophene copolymer, and P(IDT-NDI).

7. A dual-spectral response photodetector according to any one of claims 1-4 and 6, characterized in that, The thickness of the hybrid layer is 0.8~2 µm.

8. A dual-spectral response photodetector according to claim 6, characterized in that, The doping amount of the macromolecular polymer material is 1% to 10%.

9. A dual-spectral response photodetector according to claim 1, characterized in that, The material of the receptor layer includes any one or more of fullerene derivatives, perylene diimide derivatives, or naphthalene diimide derivatives.

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