Narrowband photoelectric detector based on local plasma enhanced perovskite and preparation method

Abstract

The invention discloses a perovskite narrow-band photoelectric detector based on local plasma enhancement and a preparation method thereof, and the perovskite narrow-band photoelectric detector utilizes specially-made metal nanoparticles to accurately adjust a local surface plasma resonance band of the perovskite narrow-band photoelectric detector, thereby achieving the purpose of overlapping with a perovskite target narrow-band response range. Therefore, penetrating long-wavelength incident photons and an electromagnetic field around the metal nanoparticles generate strong coupling interaction, light absorption is effectively improved through a near-field enhancement induction excitation effect, light current is remarkably enhanced, a local surface plasmon resonance band is regulated and controlled, harmonious enhancement of a detection wave band is achieved, and the detection sensitivity is improved. And the detection performance regulation and control enhancement in the spectral response range of the photoelectric detector is further realized.

Description

Technical Field

[0001] The present invention relates to the technical field of photodetectors, and particularly relates to a localized plasmon-enhanced perovskite narrow-band photodetector and a preparation method thereof. Background Art

[0002] Enhancing the absorption of materials at specific wavelengths through plasmon resonance is a common method for preparing narrow-band photodetectors. For example, a photodetector and a preparation method thereof disclosed in Publication No. CN116193875A introduce silver nanoparticles into the perovskite active layer. Through the excitation of local surface plasmon resonance, the prepared photodetector can effectively improve the detection capabilities in different detection bands. However, since this disclosure uses conventional silver nanoparticles, when the silver nanoparticles form a nearly three-dimensional Schottky contact with the perovskite active layer, it affects the crystal structure of the perovskite and changes its surface morphology. In addition, it is difficult for this perovskite photodetector to achieve tunable enhancement of the detection band, thereby restricting its practical application in the field of high-performance photodetection. Summary of the Invention

[0003] In view of this, the present disclosure provides a localized plasmon-enhanced perovskite narrow-band photodetector and a preparation method thereof, which are used to solve the problem that currently, preparing a perovskite narrow-band photodetector using conventional noble metal nanoparticles will affect the crystal structure of the perovskite and change its surface morphology, resulting in the perovskite photodetector being difficult to achieve tunable enhancement of the detection band and restricting its practical application in the field of high-performance photodetection.

[0004] To achieve the above-mentioned invention purpose, in a first aspect, the localized plasmon-enhanced perovskite narrow-band photodetector described in the present disclosure includes a patterned glass substrate, a metal nanoparticle layer integrated on the glass substrate, and a perovskite light absorption layer disposed on the metal nanoparticle layer;

[0005] The metal nanoparticle layer is integrated by gold nanoparticles, silver nanoparticles or gold nanorod particles, and the local surface plasmon resonance bands of the gold nanoparticles, silver nanoparticles and gold nanorod particles correspond to the perovskite target narrow-band response range.

[0006] Preferably, the preparation method of the gold nanoparticles includes:

[0007] According to the molar ratio of HAuCl 4 to trisodium citrate being 0.2 - 0.3:1, add the HAuCl 4 solution to deionized water. After heating to boiling under vigorous stirring, add the trisodium citrate solution, continue boiling and stirring until the solution color turns wine red, and perform centrifugation to obtain the gold nanoparticles.

[0008] Preferably, the method for preparing the silver nanoparticles includes:

[0009] Dissolve sodium borohydride and trisodium citrate in deionized water according to the mass ratio of sodium borohydride to trisodium citrate of 0.03 - 0.04:1, heat to 50 - 70 °C under dark conditions and stir vigorously to form a homogeneous mixed solution;

[0010] Add the silver nitrate solution dropwise to the mixed solution according to the molar ratio of silver nitrate to trisodium citrate of 0.05 - 0.07:1, raise the temperature to 85 - 95 °C and adjust the pH value of the system to 10 - 11. After the color of the solution changes significantly, continue heating for 15 - 25 minutes. Wash the silver nanoparticles obtained by centrifugation to remove the unreacted reducing agent, and then obtain the silver nanoparticles.

[0011] Preferably, the method for preparing the gold nanorod particles includes:

[0012] Mix HAuCl 4 with cetyltrimethylammonium bromide according to the molar ratio of 0.02 - 0.03:1. Mix the HAuCl 4 aqueous solution with the cetyltrimethylammonium bromide solution. Then, add the NaBH 4 solution according to the molar ratio of HAuCl 4 to NaBH 4 of 40 - 45:1, stir vigorously and age at room temperature to obtain a seed solution;

[0013] Dissolve cetyltrimethylammonium bromide and sodium oleate in deionized water according to the mass ratio of cetyltrimethylammonium bromide to sodium oleate of 7 - 7.5:1, heat to 60 - 80 °C, and stir until the solution becomes colorless and transparent; according to the molar ratio of AgNO 3 to cetyltrimethylammonium bromide of 0.1 - 0.2:5, cool the colorless transparent solution to 25 - 35 °C and then add the AgNO 3 solution. After standing for 10 - 20 minutes, add the HAuCl 4 solution according to the molar ratio of cetyltrimethylammonium bromide to HAuCl 4 of 90 - 110:1 and stir. When the solution changes from colorless to yellow, stop stirring and stand for 10 - 20 minutes, then continue stirring until the solution changes from yellow back to colorless; adjust the pH value of the system to 10 - 11, and add the ascorbic acid solution according to the molar ratio of HAuCl 4 to ascorbic acid of 3 - 3.2:1 and stir vigorously to obtain a growth solution;

[0014] Inject the seed solution into the growth solution at a volume ratio of the seed solution to the growth solution of 0.035 - 0.045:100. After vigorous stirring, let it stand at 25 - 35 °C for 11 - 13 hours, and then centrifuge to remove the supernatant to obtain the gold nanorod particles.

[0015] Preferably, the perovskite light absorption layer is a perovskite microcrystalline film, and the material of the perovskite microcrystalline film is ABX 3 structure, where the A site is an organic cation, the B site is a divalent metal cation, and the X site is a halogen anion.

[0016] Preferably, the material of the perovskite microcrystalline film is selected from one of methylammonium lead iodide, methylammonium lead bromide, and methylammonium lead chloride.

[0017] Preferably, the thickness of the perovskite microcrystalline film is 50 - 250 μm.

[0018] Preferably, the narrowband photodetector adopts a lateral structure.

[0019] In a second aspect, a method for preparing the perovskite narrowband photodetector according to any one of the first aspects of the present disclosure includes:

[0020] Prepare a metal nanoparticle suspension of gold nanorod particles, silver nanoparticles, or gold nanoparticles, and use the metal nanoparticle suspension to prepare the metal nanoparticle layer on the patterned glass substrate by electrostatic adsorption self-assembly method.

[0021] Preferably, grow the perovskite light absorption layer on the metal nanoparticle layer by the inverse temperature method or the anti-solution method.

[0022] Preferably, before the electrostatic adsorption, clean and hydrophilize the patterned ITO glass substrate.

[0023] Advantages of the present invention:

[0024] For the localized plasmon-enhanced perovskite narrowband photodetector described in the present disclosure, by strategically designing the preparation method of metal nanoparticles, its local surface plasmon resonance (Localized Surface Plasmon Resonance, LSPR) band is precisely adjusted to completely coincide with the target narrowband response range, so that the penetrated long-wavelength incident photons strongly couple with the electromagnetic field around the metal nanoparticles, and the light absorption is effectively improved through the near-field enhancement-induced excitation (Near-Field Enhancement-induced Excitation, NFEE) effect, thereby significantly enhancing the photocurrent;

[0025] In addition, compared with the original thin-film-based perovskite photodetector device, further growing a perovskite light absorption layer on the metal nanoparticle layer does not change the morphology and crystal structure of the original perovskite light absorption layer, enabling the photodetector of the present disclosure to be constructed of perovskite microcrystals, thereby having higher stability;

[0026] Meanwhile, the present disclosure provides a plasma-enhanced perovskite narrow-band photodetector with adjustable detection band, which can achieve the function of light discrimination without any additional optical elements;

[0027] Furthermore, the photodetector of the present invention can achieve modulation of the spectral response range, and has the characteristics of simple preparation process and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Through the description of the embodiments of the present disclosure with reference to the following drawings, the above and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:

[0029] Figure 1 is a schematic structural diagram of the present invention, and the arrows in the figure indicate the incident direction of incident light;

[0030] Figure 2 Among them, (a), (b), and (c) are SEM images of silver nanoparticles, gold nanoparticles, and gold nanorods in Embodiments 1-3 of the present disclosure respectively;

[0031] Figure 3 Among them, (a)-(a'), (b)-(b'), and (c)-(c') are SEM comparison diagrams of perovskite in Embodiments 1-3 of the present disclosure and the comparative example respectively; in the figure, MAPbCl 3 -AgNP, MAPbBr 3 -AuNP, and MAPbI 3 -AuNR are abbreviated as w.AgNP, w.AuNP, and w.AuNR respectively;

[0032] Figure 4 is the XRD diffraction pattern comparison of perovskite in Embodiments 1-3 of the present disclosure and the comparative example;

[0033] Figure 5 is the external quantum efficiency comparison diagram of the photodetector devices in Embodiments 1-3 of the present disclosure and the comparative example;

[0034] Figure 6 is the responsivity comparison diagram of the photodetector devices in Embodiments 1-3 of the present disclosure and the comparative example;

[0035] Figure 7 is the specific detectivity comparison diagram of the photodetector devices in Embodiments 1-3 of the present disclosure and the comparative example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present disclosure will be described based on embodiments. However, it should be noted that the present disclosure is not limited to these embodiments. In the following detailed description of the present disclosure, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand the present disclosure.

[0037] For the local plasmon enhanced perovskite narrow-band photodetector of the present disclosure, the technical concept is: preparing special noble metal nanoparticles to regulate their local surface plasmon resonance band so that it overlaps with the wavelength band of the perovskite narrow-band response, thereby achieving tunable enhancement of the detection wavelength band.

[0038] The preparation methods of the noble metal nanoparticles provided in the embodiments of the present disclosure include gold nanoparticles, silver nanoparticles and gold nanorod particles, and their preparation methods are as follows:

[0039] 1. The preparation method of gold nanorod particles is as follows:

[0040] (1) Mix HAuCl 4 and cetyltrimethylammonium bromide at a molar ratio of 0.02 - 0.03:1. Mix the HAuCl 4 aqueous solution and the cetyltrimethylammonium bromide solution. Then, add NaBH 4 solution at a molar ratio of HAuCl 4 to NaBH 4 of 40 - 45:1. Stir vigorously and age at room temperature to obtain a seed solution;

[0041] (2) Mix cetyltrimethylammonium bromide and sodium oleate at a mass ratio of 7 - 7.5:1. Dissolve cetyltrimethylammonium bromide and sodium oleate in deionized water, heat to 60 - 80 °C, and stir until the solution becomes colorless and transparent; add AgNO 3 solution at a molar ratio of AgNO 3 to cetyltrimethylammonium bromide of 0.1 - 0.2:5 after cooling the colorless transparent solution to 25 - 35 °C. Let it stand for 10 - 20 minutes, then add HAuCl 4 solution at a molar ratio of cetyltrimethylammonium bromide to HAuCl 4 of 90 - 110:1 and stir. When the solution changes from colorless to yellow, stop stirring and let it stand for 10 - 20 minutes, then continue stirring until the solution returns from yellow to colorless; adjust the pH value of the system to 10 - 11, and add ascorbic acid solution at a molar ratio of HAuCl 4 to ascorbic acid of 3 - 3.2:1 and stir vigorously to obtain a growth solution;

[0042] (3) Inject the seed solution into the growth solution at a volume ratio of the seed solution to the growth solution of 0.035 - 0.045:100. After vigorous stirring, let it stand at 25 - 35 °C for 11 - 13 hours, and then centrifuge to remove the supernatant to obtain the gold nanorod particles.

[0043] 2. The preparation method of silver nanoparticles is as follows:

[0044] (1) Dissolve sodium borohydride and trisodium citrate in deionized water at a mass ratio of sodium borohydride to trisodium citrate of 0.03 - 0.04:1. Heat it to 50 - 70 °C under dark conditions and stir vigorously to form a homogeneous mixed solution;

[0045] (2) Add the silver nitrate solution dropwise to the mixed solution at a molar ratio of silver nitrate to trisodium citrate of 0.05 - 0.07:1. Raise the temperature to 85 - 95 °C and adjust the pH value of the system to 10 - 11. After the color of the solution changes significantly, continue heating for 15 - 25 minutes, and wash the silver nanoparticles obtained by centrifugation to remove the unreacted reducing agent to obtain the silver nanoparticles.

[0046] 3. The preparation method of gold nanoparticles is as follows:

[0047] (3) According to the molar ratio of HAuCl 4 to trisodium citrate of 0.2 - 0.3:1, add the HAuCl 4 solution to deionized water. After heating to boiling under vigorous stirring, add the trisodium citrate solution, continue boiling and stirring until the color of the solution turns wine - red, and centrifuge to obtain the gold nanoparticles.

[0048] The preparation method of the local - plasmon - enhanced perovskite narrow - band photodetector described in this disclosure adopts the following technical steps:

[0049] 1. Use the patterned ITO glass as the substrate and perform a hydrophilic treatment on it;

[0050] 2. Attach metal nanoparticles to the patterned ITO glass substrate by electrostatic adsorption to form a metal nanoparticle layer;

[0051] 3. Prepare a metal nanoparticle suspension and formulate a perovskite precursor solution. Through the inverse - temperature method or the anti - solution method, grow perovskite crystals on the patterned ITO glass substrate attached with the metal nanoparticle layer at 400 revolutions per minute;

[0052] 4. Use the spin - coating method to encapsulate the hybrid device with polymethyl methacrylate (PMMA) to obtain a narrow - band photodetector.

[0053] The following are the preferred embodiments of the present disclosure and the corresponding comparative examples. Through the comparative analysis of the data of the embodiments and the comparative examples, the beneficial effects of the perovskite narrow-band photodetector of the present invention are illustrated.

[0054] Example 1

[0055] In this example, a lateral structure based on local plasmon-enhanced perovskite narrow-band photodetector is prepared. As Figure 1 shown, the perovskite narrow-band photodetector based on the lateral structure in this example is composed of a patterned ITO glass substrate 1, a metal nanoparticle layer 2 integrated on the patterned ITO glass substrate 1, and a perovskite light absorption layer 3 disposed on the metal nanoparticle layer 2. The specific preparation steps are as follows:

[0056] 1. The patterned ITO glass substrate is sequentially cleaned in an ultrasonic cleaner for 15 minutes each in acetone, deionized water, and absolute ethanol, and then dried with nitrogen for standby.

[0057] 2. Prepare a suspension of gold nanorods (metal nanoparticles):

[0058] (1) Prepare a gold nanorod seed solution: First, mix 2.5 mL of 5 mM HAuCl 4 with 2.5 mL of 0.2 M cetyltrimethylammonium bromide solution in a 10 mL scintillation vial. Then, after diluting 0.3 mL of 0.01 M NaBH 4 solution to 0.5 mL with deionized water, inject it into the above mixed solution and stir vigorously for 2 minutes. Finally, age the seed solution at room temperature for 30 minutes.

[0059] (2) Prepare a gold nanorod growth solution: Dissolve 1.8 g of cetyltrimethylammonium bromide and 246.8 mg of sodium oleate in 50 mL of deionized water, and stir and heat in a water bath to 70 °C until the solution becomes colorless and transparent. After cooling the mixed solution to 30 °C, add 3.6 mL of a 4×10 -3 M AgNO 3 solution, let it stand for 15 minutes, then continue to add 50 mL of a 1×10 -3 M HAuCl 4 solution and stir. The solution gradually changes from colorless to yellow. Stop stirring and let it stand for 15 minutes, then continue to stir for 90 minutes until the solution returns from yellow to colorless. Subsequently, add 0.42 mL of 37 wt% hydrochloric acid to adjust the pH value to 10.5, and stir slowly for 15 minutes. Continue to add 0.25 mL of 0.064 M ascorbic acid solution and stir vigorously for 30 seconds.

[0060] (3) Inject 0.04 mL of the seed solution into the growth solution, stir vigorously for 30 seconds, and then let it stand at 30 °C for 12 hours. Centrifuge the final product at 7000 rpm for 15 minutes, remove the supernatant, repeat the process to improve the separation effect, and finally redisperse it in deionized water to form a gold nanorod suspension.

[0061] 3. Hydrophilically treat the cleaned patterned ITO glass substrate. By means of electrostatic adsorption self-assembly, immerse the patterned ITO glass substrate in the gold nanorod suspension until a uniformly distributed layer of gold nanorods is integrated on the substrate.

[0062] 4. Add lead chloride or lead bromide (PbX 2 (X = Cl, Br)) corresponding to methylammonium hydrobromide or methylammonium hydrochloride (MAX(X = Cl, Br)) to dimethylformamide / dimethyl sulfoxide (DMF / DMSO) at a molar ratio of 1:1, and place it on a magnetic stirring table and stir until the powder is completely dissolved. After complete dissolution, filter it through a filter with a diameter of 0.22 μm, and pour the filtered mixed solution into a 40 mm crystallizing dish pre-placed with the patterned ITO glass substrate. Open the crystallizing dish to allow the anti-solvent to diffuse, place it in a 70 mm crystallizing dish containing V1 (20 mL) of dichloromethane, and maintain it at 400 rpm on a stirring table. At room temperature, after about 4 hours, take out the patterned ITO glass substrate from the solution and anneal it in a vacuum drying oven at 70 °C for 1 hour to obtain MAPbBr 3 -AuNP narrowband photodetector and MAPbCl 3 -AgNP narrowband photodetector.

[0063] 5. Dissolve lead iodide (PbI 2 ) and methylammonium iodide (MAI) in 1 / 4V1 γ-butyrolactone (GBL, ≥99%), and then mix it with 1,2-dichlorobenzene (DCB, 99%), and place it on a magnetic stirring table and stir until the powder is completely dissolved. After complete dissolution, filter it through a filter with a diameter of 0.22 μm, and then pour the filtered mixed solution into a crystallizing dish (40 mm) pre-placed with the patterned ITO glass substrate. Heat the crystallizing dish to 110 °C under continuous stirring at 400 rpm. After 30 minutes, take out the patterned ITO glass substrate from the solution and anneal it in a vacuum drying oven at 70 °C for 1 hour to obtain MAPbI 3 -AuNR narrowband photodetector.

[0064] 6. Encapsulate the narrowband photodetector with a polymethyl methacrylate (PMMA) solution. The selected spin coating rate is 2000 revolutions per minute, and the spin coating time is 60 seconds.

[0065] Example 2

[0066] In this embodiment, a lateral-structure local plasmon-enhanced perovskite narrow-band photodetector is prepared. Different from Embodiment 1, the metal nanoparticle suspension in Step 2 and its preparation method are different, while other steps are the same as those in Embodiment 1. The metal nanoparticles in this embodiment are silver nanoparticles, and the preparation process of the silver nanoparticle suspension is as follows:

[0067] (4) Dissolve 0.0034 g of sodium borohydride and 0.106 g of trisodium citrate in 180 mL of deionized water, heat to 60 °C under dark conditions, and vigorously stir for 30 minutes to form a homogeneous mixed solution.

[0068] (5) Gradually add 20 mL of 1.22×10 -3 M silver nitrate solution dropwise into the mixed solution, and further raise the temperature to 90 °C. When the temperature reaches 90 °C, adjust the pH value of the solution to 10.5 with 0.1 M sodium hydroxide solution. After the solution color changes significantly, continue heating for 20 minutes. After the reaction stops, cool the silver nanoparticle suspension to room temperature, then centrifuge and wash three times to remove the unreacted reducing agent, and finally redisperse it in deionized water to form a silver nanoparticle suspension.

[0069] Embodiment 3

[0070] In this embodiment, a lateral-structure local plasmon-enhanced perovskite narrow-band photodetector is prepared. Different from Embodiment 1, the metal nanoparticle suspension in Step 2 and its preparation method are different, while other steps are the same as those in Embodiment 1. The metal nanoparticles in this embodiment are gold nanoparticles, and the preparation process of the gold nanoparticle suspension is as follows:

[0071] (1) Add 1.5 mL of a 25.4 mM HAuCl 4 ·3H 2 O solution and 146 mL of deionized water into a three-necked round-bottom flask, and heat to boiling under vigorous stirring.

[0072] (2) Quickly add 0.9 mL of a 50 mg / mL trisodium citrate solution, continue boiling and stirring for 20 minutes until the solution color turns wine red to form a gold nanoparticle suspension.

[0073] Comparative Example

[0074] This comparative example prepares a perovskite narrow-band photodetector based on a lateral structure, including the following steps:

[0075] 1. Clean the patterned ITO glass substrate in an ultrasonic cleaner for 15 minutes each in the order of acetone, deionized water, and absolute ethanol, and dry it with nitrogen for later use;

[0076] 2. Add lead chloride or lead bromide (PbX 2 (X = Cl, Br)) and methylammonium hydrobromide or methylammonium hydrochloride (MAX(X = Cl, Br)) in a molar ratio of 1:1 to dimethylformamide / dimethyl sulfoxide (DMF / DMSO). Place it on a magnetic stirring table and stir until the powder is completely dissolved. Then filter it through a filter with a diameter of 0.22 μm. Pour the filtered mixed solution into a 40-mm crystallizing dish pre-placed with a patterned ITO glass substrate. Open the crystallizing dish to allow the anti-solvent to diffuse, and place it in a 70-mm crystallizing dish containing V1 (20 mL) of dichloromethane. Keep it on the stirring table at 400 rpm. At room temperature, after about 4 hours, take out the patterned ITO glass substrate from the solution and anneal it in a vacuum drying oven at 70 °C for 1 hour to obtain MAPbBr 3 narrowband photodetectors and MAPbCl 3 narrowband photodetectors.

[0077] 3. Dissolve lead iodide (PbI 2 ) and methylammonium iodide (MAI) in 1 / 4V1 γ-butyrolactone (GBL, ≥99%). Then mix it with 1,2-dichlorobenzene (DCB, 99%). Place it on a magnetic stirring table and stir until the powder is completely dissolved. Then filter it through a filter with a diameter of 0.22 μm. Pour the filtered mixed solution into a crystallizing dish (40 mm) pre-placed with a patterned ITO glass substrate. While continuously stirring at 400 rpm, heat the crystallizing dish to 110 °C. After 30 minutes, take out the patterned ITO glass substrate from the solution and anneal it in a vacuum drying oven at 70 °C for 1 hour to obtain MAPbI 3 narrowband photodetectors.

[0078] 4. Encapsulate the narrowband photodetectors with a polymethyl methacrylate (PMMA) solution at a spin-coating rate of 2000 revolutions per minute for 60 seconds.

[0079] Comparative analysis examples

[0080] 1. Scanning electron microscope (SEM) comparative analysis:

[0081] (1) The SEM images of the metal nanoparticles prepared in Examples 1-3 are as Figure 2 shown.

[0082] (2) Compare the SEM images of the perovskites integrated with metal nanoparticles in Examples 1-3 and the perovskites without integrated metal nanoparticles in the comparative examples. Specifically, for MAPbI 3 -AuNR based on metal nanorods, MAPbBr 3 -AuNP based on silver nanoparticles, and MAPbCl based on gold nanoparticles3 -AgNP was respectively compared and analyzed with the corresponding perovskites in the comparative examples, and the results are as Figure 3 shown in the three groups of comparative figures of (a)-(a'), (b)-(b), and (c)-(c).

[0083] 2. X-ray diffraction (XRD) comparative analysis:

[0084] In this disclosure, the XRD patterns of the perovskites integrated with metal nanoparticles in Examples 1-3 were compared with those of the perovskites without integrated metal nanoparticles in the comparative examples. Specifically, for MAPbI 3 -AuNR based on metal nanorods, MAPbBr 3 -AuNPP based on silver nanoparticles, and MAPbCl 3 -AgNP based on gold nanoparticles were respectively compared with the corresponding XRD diffraction patterns of the perovskites in the comparative examples, and the results are as Figure 4 shown.

[0085] 3. External quantum efficiency and responsivity comparative analysis:

[0086] In this disclosure, the external quantum efficiency and responsivity of the perovskites integrated with metal nanoparticles in Examples 1-3 were compared with those of the perovskites without integrated metal nanoparticles in the comparative examples. Specifically, for CH 3 NH 3 PbI 3 -AuNR based on metal nanorods, MAPbBr 3 -AuNP based on silver nanoparticles, and MAPbCl 3 -AgNP based on gold nanoparticles were respectively compared with the corresponding photodetectors in the comparative examples for external quantum efficiency and responsivity. The results are respectively as Figure 5 and Figure 6 shown. In Figure 5 , the abscissa represents the detected wavelength, and the ordinate represents the quantum efficiency, that is, the ratio of the average number of photoelectrons generated per unit time to the number of incident photons at a specific wavelength; in Figure 6 , the abscissa represents the detected wavelength, and the ordinate represents the spectral responsivity.

[0087] Through Figure 5 , Figure 6 the comparison results show that the photodetector devices prepared in Examples 1-3 of this disclosure exhibit good wavelength selectivity, and their performance has been significantly improved. MAPbCl 3 -AgNP, MAPbBr 3 -AuNP, and MAPbI 3 -AuNR photodetectors respectively show up to 171 A·W -1 @410 nm, 269 A·W -1@550nm and 453 A·W -1 The peak responsivity is at 830 nm, and the full width at half maximum (FWHM) is only in the wavelength range of 20 - 30 nm.

[0088] 4. Comparative analysis of specific detectivity:

[0089] The present disclosure compares the external quantum efficiency of the perovskites integrated with metal nanoparticles in Examples 1 - 3 and the perovskites without integrated metal nanoparticles in the comparative examples. Specifically, for MAPbI 3 -AuNR based on metal nanorods, MAPbBr 3 -AuNP based on silver nanoparticles, and MAPbCl 3 -AgNP based on gold nanoparticles are respectively compared with the corresponding photodetectors in the comparative examples in terms of external quantum efficiency and responsivity. The results are as shown in Figure 7 the figure, where the abscissa represents the detected wavelength and the ordinate represents the specific detectivity.

[0090] Figure 7 The comparison results of 3 MAPbCl 3 -AgNP, MAPbBr 3 -AuNP, and MAPbI 3 -AuNR photodetectors show that they respectively achieve ultra-high specific detectivities of 1.26×10 14 Jones, 1.84×10 14 Jones, and 3.13×10 14 Jones. Compared with the original photodetector devices without MNPs modification in the comparative examples, they are respectively increased by 1.36 times, 1.08 times, and 1.52 times.

[0091]

[0092] In summary, for the plasma-enhanced perovskite narrow-band photodetector of the present invention, by preparing specific metal nanoparticles and then regulating their localized surface plasmon resonance bands to overlap with the wavelength band of the narrow-band response of the perovskite, enhanced detection wavelength band tunability is achieved, and further enhanced detection performance regulation within the spectral response range of the photodetector is realized.

[0093] In addition, the photodetector of the present disclosure adopts a lateral structure. Compared with the narrow-band photodetector with a vertical structure, since both the incident light surface and the source-drain electrodes are located on the same side of the substrate, the preparation and testing are simpler and more convenient.

[0094] The above-described embodiments are only used to illustrate the implementation manners of the present disclosure. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present disclosure. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications, equivalent substitutions, improvements, etc. can be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the appended claims.

Claims

1. A narrow-band photodetector based on localized plasma enhanced perovskite, characterized in that: include: A patterned glass substrate, a metal nanoparticle layer integrated on the glass substrate, and a perovskite light absorbing layer disposed on the metal nanoparticle layer; The metal nanoparticle layer is integrated with gold nanoparticles, silver nanoparticles or gold nanorod particles, and the local surface plasma resonance bands of the gold nanoparticles, silver nanoparticles and gold nanorod particles correspond to the target narrow-band response range of perovskite.

2. The localized plasmon enhanced perovskite narrowband photodetector according to claim 1, characterized in that: The method for preparing the gold nanoparticles comprises: According to the molar ratio of HAuCl4 to trisodium citrate of 0.2-0.3:1, HAuCl4 solution is added to deionized water, heated to boiling under vigorous stirring, and then trisodium citrate solution is added, and boiling and stirring are continued until the color of the solution changes to wine red, and the gold nanoparticles are obtained by centrifugation.

3. The localized plasmon enhanced perovskite narrow-band photodetector according to claim 1, characterized in that: The method for preparing the silver nanoparticles comprises: Sodium borohydride and trisodium citrate were dissolved in deionized water at a mass ratio of 0.03-0.04:1, heated to 50-70° C. in the dark and stirred vigorously to form a uniform mixed solution; According to the molar ratio of silver nitrate to trisodium citrate of 0.05-0.07:1, the silver nitrate solution is added dropwise to the mixed solution, the temperature is raised to 85-95° C. and the pH value of the system is adjusted to 10-11. After the color of the solution changes significantly, the heating is continued for 15-25 minutes, and the silver nanoparticles obtained by centrifugation are washed to remove the unreacted reducing agent to obtain the silver nanoparticles.

4. The localized plasmon enhanced perovskite narrow-band photodetector according to claim 1, characterized in that: The method for preparing the gold nanorod particles comprises: The molar ratio of HAuCl4 to hexadecyltrimethylammonium bromide is 0.02-0.03:1, the HAuCl4 aqueous solution and the hexadecyltrimethylammonium bromide solution are mixed, and then the NaBH4 solution is added at a molar ratio of HAuCl4 to NaBH4 of 40-45:1, and the mixture is vigorously stirred and aged at room temperature to obtain a seed solution; The mass ratio of hexadecyltrimethylammonium bromide to sodium oleate is 7-7.5:1, and the hexadecyltrimethylammonium bromide and sodium oleate are dissolved in deionized water, the temperature is raised to 60-80°C, and the solution is stirred until it is colorless and transparent; the molar ratio of AgNO3 to hexadecyltrimethylammonium bromide is 0.1-0.2:5, and the colorless transparent solution is cooled to 25-35°C, and then the AgNO3 solution is added, and after standing for 10-20 minutes, the molar ratio of hexadecyltrimethylammonium bromide to HAuCl4 is 90-110:1, and the HAuCl4 solution is added and stirred until the solution changes from colorless to yellow, the stirring is stopped, and the solution is allowed to stand for 10-20 minutes, and the stirring is continued until the solution returns from yellow to colorless; the pH value of the system is adjusted to 10-11, and the ascorbic acid solution is added according to the molar ratio of HAuCl4 to ascorbic acid of 3-3.2:1, and the growth solution is obtained; The seed solution is injected into the growth solution at a volume ratio of 0.035-0.045:100, and after vigorous stirring, the solution is allowed to stand at 25-35° C. for 11-13 hours, and the supernatant is removed by centrifugation to obtain the gold nanorod particles.

5. The localized plasmon enhanced perovskite narrow-band photodetector according to any one of claims 1 to 4, characterized in that: The perovskite light absorption layer is a perovskite microcrystalline film, the thickness of the perovskite microcrystalline film is 50 to 250 μm, and the perovskite microcrystalline film material is an ABX3 structure, wherein the A position is an organic cation, the B position is a positive divalent metal cation, and the X position is a halogen anion.

6. The localized plasmon enhanced perovskite narrow-band photodetector according to claim 5, characterized in that: The perovskite microcrystalline film material is selected from one of lead methylammonium iodide, lead methylammonium bromide and lead methylammonium chloride.

7. The localized plasmon enhanced perovskite narrow-band photodetector according to claim 6, characterized in that: The narrow-band photoelectric detector adopts a lateral structure.

8. The method for preparing the perovskite narrow-band photodetector according to any one of claims 1 to 7, characterized in that: include: A metal nanoparticle suspension of gold nanorod particles, silver nanoparticles or gold nanoparticles is prepared, and the metal nanoparticle layer is prepared on the patterned glass substrate by using the metal nanoparticle suspension through an electrostatic adsorption self-assembly method.

9. The method for preparing a perovskite narrow-band photodetector according to claim 8, characterized in that: A perovskite light absorbing layer is grown on the metal nanoparticle layer by using an inversion method or a reverse solution method.

10. The method for preparing a perovskite narrow-band photodetector according to claim 9, characterized in that: Before the electrostatic adsorption is performed, the patterned ITO glass substrate is cleaned and subjected to a hydrophilic treatment.

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