Wavelength dependent self-powered bipolar photoelectric detector

Abstract

The invention relates to the technical field of wavelength-dependent self-powered bipolar photoelectric detectors, in particular to a wavelength-dependent self-powered bipolar photoelectric detector which is prepared by compounding near-infrared photothermal dye and perovskite and comprises a C film, a CsBi3I10 modified film, an In2O3 film, an ITO film and a glass sheet layer which are sequentially arranged from top to bottom. The CsBi3I10 modified thin film is prepared by modifying a CsBi3I10 thin film through methyl benzene sulfonate (IR813). According to the application, the IR813 is used for modifying the CsBi3I10 film, so that the photovoltaic effect of the In2O3 / CsBi3I10 heterojunction and the photo-thermoelectric effect of the IR813 under different wavelength light compete with each other, the bipolar photoresponse is generated, and the environment-friendly and high-stability material is selected to protect the environment and prolong the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of wavelength-dependent self-powered bipolar photodetectors, and in particular to a wavelength-dependent self-powered bipolar photodetector. Background Art

[0002] In order to improve the performance of perovskite photodetectors, many methods have been proposed to improve the responsivity, including oxide thin film coating, optimization of perovskite growth conditions, rare earth ion doping, etc. On the other hand, due to the needs of military detection and other aspects, instant imaging, fast optical communication, and high-speed dynamic monitoring are highly required for ultrafast response photodetectors. Since metal nanoparticles have the local surface plasma resonance (LSPR) effect, the metal nanoparticles interact with the fluorescence generated by the excitation of excitons, accelerating the radiative decay rate of nearby excitons, thereby reducing the possibility of quenching through non-radiative recombination, enhancing the absorption and emission of light. Therefore, introducing metal nanoparticles onto the surface of perovskite can enhance the responsivity of the detector and significantly reduce the response time.

[0003] A preparation method and application of a high-speed perovskite photodetector with the publication number CN119384197A promote the longitudinal growth of perovskite crystals, which is beneficial to the collection and transport of carriers, and the device has high stability and response.

[0004] A method for preparing a perovskite photodetector with the publication number CN118541000A significantly improves the optoelectronic performance of the perovskite photodetector through the preparation of perovskite precursor solution, the introduction of nano-grating structure, the morphology optimization of electrodes, and interface engineering treatment. Especially the introduction of the nano-grating structure optimizes the light capture and conversion efficiency, thereby enhancing the spectral response and sensitivity of the detector.

[0005] In summary, the current research on perovskite photodetectors mainly focuses on improving their response speed and responsivity. And most perovskite photodetectors are unidirectional light response devices with relatively single functions, making it difficult to meet the requirements of complex optical signal detection.

[0006] Most of the bipolar photodetectors based on metal halide perovskites use organic-inorganic hybrid lead halide perovskite materials, which have two major drawbacks: the toxicity of lead elements and poor stability. Therefore, improvement is needed. Summary of the Invention

[0007] The purpose of the present invention is to solve the deficiencies existing in the prior art, and to propose a wavelength-dependent self-powered bipolar photodetector.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A wavelength-dependent self-powered bipolar photodetector, the detector of which is prepared by compounding near-infrared photothermal dye and perovskite.

[0010] Preferably, the detector includes a C film, a CsBi3I 10 modified film, an In2O3 film, an ITO film and a glass sheet layer which are arranged in sequence from top to bottom;

[0011] The CsBi3I 10 modified film is modified from the CsBi3I 10 film by IR813.

[0012] Compared with the prior art, the present application uses IR813 to modify the CsBi3I 10 film, so that the photovoltaic effect of the In2O3 / CsBi3I 10 heterojunction competes with the photothermal-electric effect of IR813 under light of different wavelengths, thereby generating a bipolar light response, and materials that are environmentally friendly and have strong stability are selected to protect the environment and extend the service life.

[0013] Preferably, the CsBi3I 10 perovskite has a relatively small band gap, about 1.77 eV, and its absorption edge cut-off wavelength is about 700 nm; the IR813 is a near-infrared dye and has good absorbance for near-infrared light.

[0014] Furthermore, it can enhance the absorption of the CsBi3I 10 modified film for near-infrared light, thereby expanding the detection range.

[0015] Preferably, the absorption range of the CsBi3I 10 modified film is greater than that of the CsBi3I 10 film.

[0016] Furthermore, the generation of the bipolar light response is due to the competition between the photovoltaic effect of the In2O3 / CsBi3I 10 heterojunction and the photothermal-electric effect of IR813 under light of different wavelengths.

[0017] Preferably, the CsBi3I 10 modified film has a higher absorbance for the near-infrared band than the CsBi3I 10 film.

[0018] Furthermore, use IR813 to modify the CsBi3I 10The thin film is modified, which not only expands the response range of the photodetector from visible light to the near-infrared range, but also enables the generation of reverse current under near-infrared light.

[0019] Preferably, its preparation method includes the following steps:

[0020] S1. Ultrasonically clean the ITO glass with acetone, isopropyl alcohol, and deionized water for 10 min respectively. Then dry the cleaned ITO glass with a stream of N2;

[0021] S2. Dissolve an appropriate amount of In(NO3)3·xH2O in 2-methoxyethanol to prepare a 0.1 M In(NO3)3 solution. Spin-coat the In(NO3)3 solution at 500 rpm for 5 s and then at 5000 rpm for 20 s on the ITO glass to deposit a thin film;

[0022] S3. Heat the obtained thin film in air at 280 °C for 2 h to obtain an In2O3 thin film; Take 0.75 mol CsI, 2.25 mol BiI3, and 20 mg IR813 powder and add them to 1 mL of a mixed solvent (DMF:DMSO = 4:1), and then stir at 75 °C for 4 h to obtain a precursor solution;

[0023] S4. Filter the precursor solution, spin-coat the filtered precursor solution in a glove box at 500 rpm for 10 s and then at 3000 rpm for 50 s on the In2O3 / ITO substrate, and then anneal at 125 °C for 30 min to promote its crystallization;

[0024] S5. Before spin-coating In(NO3)3 and the perovskite precursor, the substrate needs to be treated with plasma for 5 min;

[0025] S6. Brush carbon paste on the top of the perovskite thin film and anneal on a hot plate at 100 °C for 10 min to obtain a carbon electrode.

[0026] Furthermore, it fully demonstrates the preparation scheme of the photodetector in this application.

[0027] The beneficial effects of the present invention are:

[0028] 1. Using IR813 to modify the CsBi3I 10 thin film, which not only expands the response range of the photodetector from visible light to the near-infrared range, but also enables the generation of reverse current under near-infrared light;

[0029] 2. The generation of bipolar light response is due to the competition between the photovoltaic effect of the In2O3 / CsBi3I 10 heterojunction and the photothermal-electric effect of IR813 under light of different wavelengths;

[0030] 3. The lead-free CsBi3I 10 perovskite is used, which is environmentally friendly and has strong stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. is a device structure diagram of a wavelength-dependent self-powered bipolar photodetector proposed by the present invention;

[0032] Figure 2 FIG. is a device responsivity diagram of a wavelength-dependent self-powered bipolar photodetector proposed by the present invention;

[0033] Figure 3 FIG. is an I-t curve diagram of a device of a wavelength-dependent self-powered bipolar photodetector proposed by the present invention under illumination of 650 nm and 813 nm with different light intensities;

[0034] Figure 4 FIG. is an I-t curve diagram of a device of a wavelength-dependent self-powered bipolar photodetector proposed by the present invention under illumination of different wavelengths. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0036] Referring to Figures 1-4 , a wavelength-dependent self-powered bipolar photodetector is prepared by compounding a near-infrared photothermal dye and a perovskite; it includes a C film, a CsBi3I 10 modified film, an In2O3 film, an ITO film, and a glass sheet layer arranged in sequence from top to bottom;

[0037] CsBi3I 10 The modified film is modified from a CsBi3I 10 film by IR813.

[0038] In the present invention, the CsBi3I 10 perovskite has a relatively small bandgap, about 1.77 eV, and its absorption edge cut-off wavelength is about 700 nm; IR813 is a near-infrared dye and has good absorption of near-infrared light.

[0039] In the present invention, the absorption range of the CsBi3I 10 modified film is larger than that of the CsBi3I 10 film.

[0040] In the present invention, the CsBi3I 10 modified film is more than CsBi3I10 The thin film has a high absorbance in the near-infrared band; after modification, the absorbance of CsBi3I 10 in the near-infrared band is greatly improved, and this breakthrough enables the detector to play an application value in fields such as near-infrared optical communication.

[0041] The detector of this application proposes the competitive relationship between the photovoltaic effect of the In2O3 / CsBi3I 10 heterojunction and the photothermal effect of IR813 under light of different wavelengths, so as to realize the flexible regulation of the photocurrent polarity; specifically, an internal built-in electric field pointing to In2O3 is formed inside the In2O3 / CsBi3I 10 heterojunction; under visible light irradiation, excitons are generated in the CsBi3I 10 -IR813 thin film and are quickly separated into free electrons and holes under the action of the built-in electric field; the photo-generated electrons then overcome the potential barrier and transfer to In2O3, while the holes migrate to the carbon electrode, thus forming a positive current; under 813nm light irradiation, only IR813 absorbs light to generate charge carriers; at the same time, due to its efficient photothermal conversion, IR813 can convert near-infrared light energy into heat energy; therefore, one side of the CsBi3I 10 -IR813 thin film is irradiated by near-infrared light, resulting in a temperature increase; due to the Seebeck effect, a thermoelectric field is generated inside the CsBi3I 10 -IR813 thin film; the thermoelectric field drives the electrons generated by IR813 to move to the side of the low-temperature CsBi3I 10 -IR813 thin film, thus forming a negative current.

[0042] In the present invention, its preparation method includes the following steps:

[0043] S1. Ultrasonically clean the ITO glass with acetone, isopropyl alcohol and deionized water for 10 min respectively. Then dry the cleaned ITO glass with N2 flow;

[0044] S2. Dissolve an appropriate amount of In(NO3)3·xH2O in 2-methoxyethanol to prepare a 0.1M In(NO3)3 solution. The In(NO3)3 solution is spin-coated on the ITO glass at 500 rpm for 5 s and 5000 rpm for 20 s to obtain a thin film;

[0045] S3. Heat the obtained thin film in air at 280 °C for 2 hours to obtain an In2O3 thin film; take 0.75 mol CsI, 2.25 mol BiI3 and 20 mg IR813 powder and add them to 1 mL of a mixed solvent (DMF:DMSO = 4:1), and then stir at 75 °C for 4 hours to obtain a precursor solution;

[0046] S4. Filter the precursor solution, spin-coat the filtered precursor solution on the In2O3 / ITO substrate in a glove box at 500 rpm for 10 s and then at 3000 rpm for 50 s, and then anneal it at 125 °C for 30 min to promote its crystallization;

[0047] S5. Before spin-coating In(NO3)3 and the perovskite precursor, the substrate needs to be treated with plasma for 5 minutes;

[0048] S6. Brush carbon paste on the top of the perovskite film and anneal it on a hot plate at 100 °C for 10 minutes to obtain a carbon electrode.

[0049] In the present invention, the photodetector of the present application proposes the competition relationship between the photovoltaic effect of the In2O3 / CsBi3I 10 heterojunction and the photothermal effect of IR813 under light of different wavelengths, so as to realize flexible regulation of the photocurrent polarity; specifically, in the In2O3 / CsBi3I 10 heterojunction, a built-in electric field pointing to In2O3 is formed; under visible light irradiation, excitons are generated in the CsBi3I 10 -IR813 film, and are quickly separated into free electrons and holes under the action of the built-in electric field; the photo-generated electrons then overcome the potential barrier and transfer to In2O3, while the holes migrate to the carbon electrode, thus forming a positive current; under 813 nm light irradiation, only IR813 absorbs light to generate charge carriers; at the same time, due to its efficient photothermal conversion, IR813 can convert near-infrared light energy into heat energy; therefore, one side of the CsBi3I 10 -IR813 film is irradiated by near-infrared light, resulting in a temperature increase; due to the Seebeck effect, a thermal electric field will be generated inside the CsBi3I 10 -IR813 film; the thermal electric field drives the electrons generated by IR813 to move to the side of the low-temperature CsBi3I 10 -IR813 film, thus forming a negative current;

[0050] And the preparation method of the photodetector of the present application: First, ultrasonically clean the ITO glass with acetone, isopropyl alcohol and deionized water for 10 min respectively; then dry the cleaned ITO glass with an N2 flow; then, dissolve an appropriate amount of In(NO3)3·xH2O in 2-methoxyethanol to prepare a 0.1 M In(NO3)3 solution; spin-coat the In(NO3)3 solution at 500 rpm for 5 s and 5000 rpm for 20 s on the ITO glass; heat the obtained thin film in air at 280 °C for 2 hours to obtain an In2O3 thin film; add 0.75 mol CsI, 2.25 mol BiI3 and 20 mg IR813 powder to 1 mL of a mixed solvent (DMF:DMSO = 4:1), and then stir at 75 °C for 4 hours to obtain a precursor solution; spin-coat the filtered precursor solution in a glove box at 500 rpm for 10 s and 3000 rpm for 50 s on the In2O3 / ITO substrate, and then anneal at 125 °C for 30 min to promote its crystallization; before spin-coating In(NO3)3 and the perovskite precursor, the substrate needs to be treated with plasma for 5 minutes; finally, brush carbon paste on the top of the perovskite thin film and anneal on a hot plate at 100 °C for 10 minutes to obtain a carbon electrode.

[0051] As described above, only the preferred specific embodiments of the present invention are given, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A wavelength-dependent self-powered bipolar photodetector, characterized in that, Its detector is prepared by compounding near-infrared photothermal dye and perovskite.

2. The wavelength-dependent self-powered bipolar photodetector according to claim 1, characterized in that, Its detector includes a C thin film, a CsBi3I 10 modified thin film, an In2O3 thin film, an ITO thin film, and a glass sheet layer, which are arranged in sequence from top to bottom; The CsBi3I 10 The modified film is composed of CsBi3I 10 The film is modified by IR813.

3. The wavelength-dependent self-powered bipolar photodetector according to claim 2, wherein: The CsBi3I 10 perovskite has a relatively small bandgap of about 1.77 eV, and its absorption edge cut-off wavelength is about 700 nm; the IR813 is a near-infrared dye with good absorbance for near-infrared light.

4. The wavelength-dependent self-powered bipolar photodetector according to claim 2, wherein: The CsBi3I 10 modified thin film has an absorption range greater than that of the CsBi3I 10 thin film.

5. The wavelength-dependent self-powered bipolar photodetector according to claim 2, characterized in that: The CsBi3I 10 modified thin film compared with CsBi3I 10 thin film has a high absorbance in the near-infrared band.

6. The wavelength-dependent self-powered bipolar photodetector according to claim 2, characterized in that: Its preparation method includes the following steps: S1. Ultrasonically clean the ITO glass with acetone, isopropyl alcohol, and deionized water for 10 min respectively. Then dry the cleaned ITO glass with an N2 stream; S2. Dissolve an appropriate amount of In(NO3)3·xH2O in 2-methoxyethanol to prepare a 0.1 M In(NO3)3 solution. Spin-coat the In(NO3)3 solution at 500 rpm for 5 s and then at 5000 rpm for 20 s on the ITO glass to deposit a thin film; S3. Heat the obtained thin film in air at 280 °C for 2 h to obtain an In2O3 thin film; Add 0.75 mol CsI, 2.25 mol BiI3, and 20 mg IR813 powder to 1 mL of a mixed solvent (DMF:DMSO = 4:1), and then stir at 75 °C for 4 h to obtain a precursor solution; S4. Filter the precursor solution, spin-coat the filtered precursor solution in a glove box at 500 rpm for 10 s and then at 3000 rpm for 50 s on the In2O3 / ITO substrate, and then anneal at 125 °C for 30 min to promote its crystallization; S5. Before spin-coating In(NO3)3 and the perovskite precursor, the substrate needs to be treated with plasma for 5 min; S6. Brush carbon paste on the top of the perovskite thin film and anneal on a hot plate at 100 °C for 10 min to obtain a carbon electrode.

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