Perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor and preparation method thereof
By using a heterojunction structure of lead-free Cs2AgBiBr6 quantum dots and pentacene single crystals, combined with a thermally released tape transfer method, the quality and performance issues of perovskite/organic semiconductor transistors were solved, achieving high-performance field-effect and charge transport properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN UNIV
- Filing Date
- 2023-03-13
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies struggle to fabricate high-quality and high-performance perovskite/organic semiconductor heterojunction transistor devices, as traditional methods may damage the perovskite layer or dissolve the organic semiconductor solvent.
A perovskite quantum dot/organic semiconductor single-crystal heterojunction transistor was fabricated using lead-free Cs2AgBiBr6 quantum dots as the photosensitive layer and pentacene single crystal as the active layer, combined with a heat-release tape-assisted transfer method, thus avoiding damage to the underlying perovskite layer.
High-quality perovskite quantum dot/organic semiconductor single-crystal heterojunction transistors were successfully fabricated, exhibiting strong field effects and high hole mobility, with an on/off ratio of 1.65×10⁵ and a hole mobility as high as 0.47 cm² V⁻¹s⁻¹.
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Figure CN116709789B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of field-effect transistor technology, specifically relating to a perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor and its fabrication method. Background Technology
[0002] In recent years, perovskite, as a novel optoelectronic semiconductor, has gained widespread favor among researchers due to its strong optical absorption, high fluorescence, long carrier diffusion length, good defect tolerance, simple preparation, and good solution processability. Benefiting from these excellent properties, perovskite semiconductors have been widely used in solar cells, X-ray detection, light-emitting diodes, and laser devices. However, the application of perovskite in the field of transistors has received relatively little attention. It has been reported that perovskite ions readily migrate due to their low binding energy. The gate field shielding effect caused by ion migration typically results in weak field effects and low mobility in perovskite at room temperature. To circumvent the low mobility of perovskite, researchers often design and synthesize perovskite / organic semiconductor heterojunction hybrid materials and use them to construct perovskite-based transistor devices. Organic semiconductors possess high mobility, which can effectively mitigate the weak field-effect properties of perovskite.
[0003] Currently, there are two main methods for constructing perovskite / organic semiconductor heterojunctions. One is vacuum evaporation, where a perovskite film is first spin-coated onto a substrate, and then an organic semiconductor is deposited on the surface of the perovskite layer via vacuum evaporation, thus forming a perovskite / organic semiconductor heterojunction. However, during the deposition process, the thermally evaporated organic semiconductor may damage the perovskite layer. The other method is spin-coating, where a perovskite film is first prepared on a substrate, and then an organic semiconductor solution is spin-coated onto the perovskite film, forming a perovskite / organic semiconductor film heterojunction. However, the solvent of the organic semiconductor may dissolve the underlying perovskite film during spin-coating. Therefore, an effective method for constructing high-quality and high-performance perovskite / organic semiconductor heterojunction transistor devices is still lacking. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the present invention aims to provide a high-performance perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor. This perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor uses lead-free perovskite (Cs₂AgBiBr₆) quantum dots as the photosensitive layer and pentacene single crystal as the active layer. Compared to traditional lead halide perovskites, Cs₂AgBiBr₆ quantum dots are lead-free and non-toxic.
[0005] Another objective of this invention is to provide a method for fabricating the aforementioned perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor. This method employs a heat-release tape-assisted transfer method, which successfully fabricates high-quality perovskite quantum dot / organic semiconductor single-crystal heterojunction transistors. The method is simple, effective, and does not damage the underlying perovskite quantum dots.
[0006] The objective of this invention is achieved through the following technical solution.
[0007] A perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor has a bottom-gate top-contact structure, comprising: a gate, an insulating layer, a photosensitive layer, an active layer, a source, and a drain. The gate, insulating layer, photosensitive layer, and active layer are arranged in parallel and connected vertically from bottom to top. The source and drain are arranged in parallel and connected to the upper surface of the active layer. The photosensitive layer is a Cs2AgBiBr6 quantum dot thin film, and the active layer is a pentacene single crystal.
[0008] In the above technical solution, the thickness of the photosensitive layer is 30-80 nm, and the thickness of the active layer is 50-120 nm.
[0009] In the above technical solution, the source and drain are gold films with a thickness of 80-150 nm.
[0010] The fabrication method of the above-mentioned perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor includes the following steps:
[0011] Step 1: Prepare a gate covered with an insulating layer as a substrate, and cover the insulating layer with a Cs2AgBiBr6 quantum dot film as the photosensitive layer;
[0012] In step 1, the method for coating the insulating layer with a Cs2AgBiBr6 quantum dot film is as follows: a solvent and Cs2AgBiBr6 quantum dots are mixed to obtain a Cs2AgBiBr6 quantum dot solution, the Cs2AgBiBr6 quantum dot solution is spin-coated onto the insulating layer, and annealing is performed to remove the solvent to obtain the Cs2AgBiBr6 quantum dot film.
[0013] In the above technical solution, the concentration of Cs2AgBiBr6 quantum dots in the Cs2AgBiBr6 quantum dot solution is 0.5-2.5 mg / mL, and the solvent is n-hexane.
[0014] In the above technical solution, the spin coating speed is 1000-2000 r / min and the time is 45-90 s.
[0015] In the above technical solution, the annealing temperature is 90-120℃, and the annealing time is 8-12 minutes.
[0016] In the above technical solution, the preparation method of Cs2AgBiBr6 quantum dots is as follows: Cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid and n-octane are mixed evenly and heated at 90-120℃ for 50-80 min to obtain a mixture. Under vigorous stirring, trimethylsilicon bromide is rapidly injected into the mixture. After the reaction is completed for 3-5 s, the system temperature is lowered to 0-5℃ by an ice-water bath, and then centrifuged. The obtained solid is Cs2AgBiBr6 quantum dots.
[0017] In the above technical solution, the ratio of the molar amounts of cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid, n-octane, and trimethylsilicon bromide is (0.69–0.72):(0.48–0.52):(0.48–0.52):(1.8–2.2):(5.8–6.2):(19–21):(0.83–0.85), where the molar amounts are in mmol and the volume parts are in mL.
[0018] Step 2: Transfer the pentacene single crystal to the upper surface of the photosensitive layer and use it as the active layer;
[0019] In step 2, the pentacene single crystal is transferred to the upper surface of the photosensitive layer using a heat-release tape.
[0020] In the above technical solution, the pentacene single crystal is prepared by micro-sublimation under atmospheric conditions.
[0021] In the above technical solution, the micro-sublimation method is as follows: an upper substrate and a lower substrate located directly below the upper substrate are placed in a sealed environment. Pentylene powder is placed on the upper surface of the lower substrate. A silicon wafer covered with a silicon dioxide layer is fixed on the lower surface of the upper substrate with the silicon dioxide layer facing down. The lower substrate is heated to 255-270°C and held for 8-12 minutes. The pentylene single crystal is formed on the surface of the silicon dioxide layer of the silicon wafer fixed under the upper substrate.
[0022] In the above technical solution, the ratio of the volume fraction of the sealed environment to the mass fraction of the pentane powder is (0.5-0.8):(1-5), and the unit of the volume fraction is cm. 3 The unit for the mass fractions is mg.
[0023] Step 3: Set the source and drain on the active layer.
[0024] The preparation method of this invention is simple, effective, and non-destructive, producing a high-quality perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor. The transferred pentacene single crystal retains good integrity. Furthermore, the underlying Cs₂AgBiBr₆ quantum dot film remains intact during the transfer process. The pentacene single crystal, as the active layer, has a smooth surface, high order, low defect density, and excellent charge transport properties. The perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor obtained by this invention exhibits a strong field-effect, with an on / off ratio reaching 1.65 × 10⁻⁶. 5 Hole mobility can be as high as 0.47 cm. 2 V -1 s -1 . Attached Figure Description
[0025] Figure 1 The X-ray diffraction pattern of the Cs2AgBiBr6 quantum dots prepared in Example 1;
[0026] Figure 2 The image shows a transmission electron microscope (TEM) image of the Cs2AgBiBr6 quantum dots prepared in Example 1.
[0027] Figure 3 This is a schematic diagram of the preparation of pentaphenyl single crystals by the micro-scan sublimation method in Example 1;
[0028] Figure 4 X-ray diffraction of the pentacene single crystal in Example 1;
[0029] Figure 5 This is a schematic diagram of transferring pentacene single crystals to the upper surface of the photosensitive layer using heat-release tape.
[0030] Figure 6 The images shown are: (a) an optical microscope image after transferring the pentacene single crystal to the photosensitive layer in Example 1; (b, c) a polarizing microscope image after transferring the pentacene single crystal to the photosensitive layer; and (d) an optical microscope image after setting the source and drain electrodes on the active layer.
[0031] Figure 7 A schematic diagram of the structure of a perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor;
[0032] Figure 8 The transfer curve (source-drain voltage V) of the perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor prepared in Example 1 is shown. D =-60V);
[0033] Figure 9 The transfer curve (source-drain voltage V) of the field-effect transistor prepared in Example 3 under the p-type mechanism. D =-60V);
[0034] Figure 10 The transfer curve (source-drain voltage V) of the field-effect transistor prepared in Example 3 under the n-type mechanism. D =60V). Detailed Implementation
[0035] The technical solution of the present invention will be further described below with reference to specific embodiments.
[0036] The sources of the drugs involved in the following examples are as follows:
[0037] Pentylene powder (purity ≥99%) was purchased from Shanghai Daran Chemical Co., Ltd.
[0038] Cesium acetate (purity ≥99.99%), bismuth acetate (purity ≥99.99%), and silver acetate (purity ≥99%) were purchased from Sigma-Aldrich.
[0039] Oleic acid (purity ≥85%), oleylamine (purity 80-90%), n-octane (purity ≥98%), trimethylsilane bromide (≥98%), n-hexane (purity ≥98%) and ethyl acetate (purity ≥98%) were purchased from Aladdin Reagent (Shanghai) Co., Ltd.
[0040] The models of the instruments involved in the following embodiments are as follows:
[0041] Current-voltage source (Keithley Source 4200), polarizing microscope (Nikon ECLIPSE Ci-POL), X-ray diffractometer (Rigaku Smartlab diffractometer), transmission electron microscope (Tecnai G2 F20 S-TWIN).
[0042] All silicon wafers were cleaned before use: they were ultrasonically cleaned in deionized water, acetone and isopropanol for 10 minutes each, and then dried with a nitrogen gun.
[0043] The method for pre-depositing gold film in the following embodiments is as follows:
[0044] 1. Modifying silicon wafers:
[0045] First, the cleaned silicon wafer (silica layer facing up, 1.5cm × 1.5cm) is placed in the plasma chamber and treated with plasma at 80W power for 10 minutes. Then, the silicon wafer is modified with octadecyltrichlorosilane. The specific process for modifying silicon wafers with octadecyltrichlorosilane is as follows: ① Place the plasma-treated silicon wafer in a glass petri dish (silica layer facing up), and place it together with the glass petri dish in a 60L vacuum oven; ② Evacuate the vacuum oven and heat it to 90℃ and maintain it for 60min (to remove moisture), add one drop (volume: 0.02mL) of octadecyltrichlorosilane to the glass petri dish through a capillary tube and seal the vacuum oven; ③ Evacuate the vacuum oven and heat it to 120℃ and maintain it for 60min, then cool it down to room temperature (20-25℃); ④ Remove the silicon wafer, and sonicate it in chloroform, n-hexane and isopropanol for 10min each, then dry it with a nitrogen gun to obtain the silicon wafer modified with octadecyltrichlorosilane.
[0046] 2. Gold plating: A copper mesh is used as a mask and attached to the silicon dioxide layer of an octadecyltrichlorosilane-modified silicon wafer to deposit a gold layer.
[0047] 3. Removing the copper mesh: Strip-shaped gold films can be prepared on silicon wafers.
[0048] Example 1
[0049] A perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor, which has a bottom-gate top-contact structure, such as... Figure 7 As shown, the device includes: a gate, an insulating layer, a photosensitive layer, an active layer, a source, and a drain. The gate, insulating layer, photosensitive layer, and active layer are arranged in parallel and connected vertically from bottom to top. The source and drain are arranged in parallel and connected to the upper surface of the active layer. The photosensitive layer is a 55nm thick Cs2AgBiBr6 quantum dot film, the active layer is a 70nm thick pentacene single crystal, the source and drain are 100nm thick gold films, and the gate, covered by an insulating layer, is a silicon wafer with a silicon dioxide layer (purchased from Beijing Qingniao Yuanxin Microsystems Technology Co., Ltd.; the silicon dioxide layer serves as the insulating layer, with a thickness of 300nm, and the silicon wafer connected to the lower surface of the silicon dioxide layer is the gate).
[0050] The fabrication of the above-mentioned perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor includes the following steps:
[0051] Step 1: The preparation method of Cs₂AgBiBr₆ quantum dots is as follows: In a 50 mL single-necked flask, cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid, and n-octane are mixed evenly and heated at 100 °C for 60 min to obtain a mixture. Under vigorous stirring, trimethylsilicon bromide is rapidly injected into the mixture. After 5 s, the system is immersed in an ice-water bath to lower the temperature to 0 °C. Then, the solution is centrifuged, and the obtained solid is Cs₂AgBiBr₆ quantum dots. The amounts of cesium acetate, bismuth acetate, and silver acetate are 0.5 mmol, oleylamine, oleic acid, and n-octane are 2 mL, 0.84 mL, 0.5 mmol, 2 mL, and 0.5 mmol respectively. Figure 1 The X-ray diffraction data shown indicate that the synthesized Cs₂AgBiBr₆ quantum dots are a pure phase and possess good crystallinity. Figure 2 The transmission electron microscopy image shown indicates that the size of the Cs2AgBiBr6 quantum dots is approximately 10 nm.
[0052] A Cs₂AgBiBr₆ quantum dot film was deposited as a photosensitive layer on a silicon dioxide layer (1.5cm × 1.5cm). A Cs₂AgBiBr₆ quantum dot solution was obtained by mixing a solvent with Cs₂AgBiBr₆ quantum dots. This solution was then spin-coated (at 1500 rpm for 60 s) onto an insulating layer. After spin-coating, the solution was annealed at 100°C for 10 min to remove the solvent, resulting in the Cs₂AgBiBr₆ quantum dot film. The concentration of Cs₂AgBiBr₆ quantum dots in the solution was 1 mg / mL, and the solvent was n-hexane.
[0053] Step 2: Prepare pentaphenyl single crystals in an atmospheric environment using the micro-sublimation method: (e.g.) Figure 3 As shown, an upper substrate and a lower substrate (1 mm apart) are placed in a sealed environment. Each substrate is a glass plate. Pentylene powder is uniformly placed on the upper surface of the lower substrate. A silicon wafer (1.5 cm × 1.5 cm) covered with a silicon dioxide layer is fixed on the lower surface of the upper substrate with the silicon dioxide layer facing down. The lower substrate is heated to 260°C and held for 10 minutes. Pentylene single crystals are formed on the surface of the silicon dioxide layer of the silicon wafer fixed under the upper substrate (the pentylene powder undergoes a gas-phase-melting-crystallization process and is finally deposited on the surface of the silicon dioxide layer). The mass of the pentylene powder is 3 mg. The surface area of the silicon dioxide layer on which the pentylene single crystals are deposited is 1.5 cm × 1.5 cm, and the volume of the sealed environment is 0.625 cm³. 3 .like Figure 4 As shown, the pentacene single crystals prepared by the micro-scan sublimation method have good crystallinity.
[0054] A single pentacene crystal was transferred to the upper surface of the photosensitive layer (Cs2AgBiBr6 quantum dot film) using a heat-release adhesive tape and used as the active layer. Figure 5 As shown, a pentacene single crystal is adhered to with thermally released adhesive tape. The tape is placed over the upper surface of the photosensitive layer with the pentacene single crystal facing down. The entire assembly is placed on a hot table, and the temperature of the hot table is raised to 90°C to cause the thermally released tape to lose its adhesiveness. The thermally released tape is then removed, leaving the pentacene single crystal on the upper surface of the photosensitive layer. Figure 6 As shown in (a) to (c), the optical microscope images demonstrate that the pentacene single crystal possesses excellent polarization characteristics, verifying its single-crystal properties. Furthermore, the optical microscope images show that the transferred pentacene single crystal maintains good integrity.
[0055] Step 3: Using a probe, transfer the pre-deposited gold film to the surface of the pentacene single crystal as the source and drain (aspect ratio 0.8), such as... Figure 6 As shown in d.
[0056] like Figure 8 As shown, a negative gate voltage and a source-drain voltage (V) are simultaneously applied to the perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor prepared in Example 1. D =-60V), the perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor exhibits a significant field effect and a high hole mobility (0.47cm). 2 V -1 s -1 ) and a high on / off ratio (1.65 × 10) 5 ).
[0057] Example 2
[0058] A perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor, which has a bottom-gate top-contact structure, such as... Figure 7 As shown, it includes: a gate, an insulating layer, a photosensitive layer, an active layer, a source, and a drain. The gate, insulating layer, photosensitive layer, and active layer are arranged in parallel and connected vertically from bottom to top. The source and drain are arranged in parallel and connected to the upper surface of the active layer. The photosensitive layer is a 70nm thick Cs2AgBiBr6 quantum dot film, the active layer is a 100nm thick pentacene single crystal, the source and drain are 110nm thick gold films, and the gate, covered by an insulating layer, is a silicon wafer with a silicon dioxide layer (purchased from Beijing Qingniao Yuanxin Microsystems Technology Co., Ltd.; the silicon dioxide layer serves as the insulating layer, with a thickness of 300nm, and the underlying silicon layer is the gate).
[0059] The fabrication of the above-mentioned perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor includes the following steps:
[0060] Step 1: The preparation method of Cs₂AgBiBr₆ quantum dots is as follows: In a 50 mL single-necked flask, cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid, and n-octane are mixed evenly and heated at 100 °C for 60 min to obtain a mixture. Under vigorous stirring, trimethylsilicon bromide is rapidly injected into the mixture. After 5 s, the system is immersed in an ice-water bath to lower the temperature to 0 °C. Then, the solution is centrifuged, and the obtained solid is Cs₂AgBiBr₆ quantum dots. The amounts of cesium acetate, bismuth acetate, and silver acetate are 0.5 mmol, oleylamine, oleic acid, and n-octane are 2 mL, 0.84 mL, 0.5 mmol, 2 mL, and 0.84 mL respectively. The synthesized Cs₂AgBiBr₆ quantum dots have good crystallinity and a size of approximately 10 nm.
[0061] A Cs₂AgBiBr₆ quantum dot film was deposited as a photosensitive layer on a silicon dioxide layer (1.5cm × 1.5cm). A Cs₂AgBiBr₆ quantum dot solution was obtained by mixing a solvent with Cs₂AgBiBr₆ quantum dots. This solution was then spin-coated onto an insulating layer (1500 r / min for 60 s). After spin-coating, the solution was annealed at 100℃ for 10 min to remove the solvent, resulting in the Cs₂AgBiBr₆ quantum dot film. The concentration of Cs₂AgBiBr₆ quantum dots in the solution was 2.5 mg / mL, and the solvent was n-hexane.
[0062] Step 2: Prepare pentaphenyl single crystals in an atmospheric environment using the micro-sublimation method: (e.g.) Figure 3 As shown, an upper substrate and a lower substrate (1 mm apart) are placed in a sealed environment. Each substrate is a glass plate. Pentylene powder is uniformly placed on the upper surface of the lower substrate. A silicon wafer (1.5 cm × 1.5 cm) covered with a silicon dioxide layer is fixed on the lower surface of the upper substrate with the silicon dioxide layer facing down. The lower substrate is heated to 265°C and held for 10 minutes. Pentylene single crystals are formed on the surface of the silicon dioxide layer of the silicon wafer fixed under the upper substrate (the pentylene powder undergoes a gas-phase-melting-crystallization process and is finally deposited on the surface of the silicon dioxide layer). The mass of the pentylene powder is 5 mg. The surface area of the silicon dioxide layer on which the pentylene single crystals are deposited is 1.5 cm × 1.5 cm, and the volume of the sealed environment is 0.75 cm³. 3 The pentacene single crystals prepared by the micro-sublimation method exhibit good crystallinity.
[0063] The pentacene single crystal was transferred to the upper surface of the photosensitive layer (Cs2AgBiBr6 quantum dot film) using thermally released adhesive tape and used as an active layer: the pentacene single crystal was adhered to the photosensitive layer with the thermally released adhesive tape covering the upper surface of the photosensitive layer with the pentacene single crystal facing down. The whole assembly was placed on a hot stage, and the temperature of the hot stage was raised to 90°C to make the thermally released adhesive tape lose its adhesiveness. The thermally released adhesive tape was then removed, leaving the pentacene single crystal on the upper surface of the photosensitive layer.
[0064] Step 3: Use a probe to transfer the pre-deposited gold film to the surface of the pentacene single crystal as the source and drain (aspect ratio of 0.8).
[0065] Simultaneously applying a negative gate voltage and source-drain voltage (V) to the perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor prepared in Example 2 D =-60V), perovskite quantum dot / organic semiconductor single-crystal heterojunction transistors exhibit significant field effects and high hole mobility (0.32cm). 2 V -1 s -1 ) and a high on / off ratio (1.2 × 10) 5 ).
[0066] Example 3
[0067] The fabrication of a Cs2AgBiBr6 quantum dot field-effect transistor includes the following steps:
[0068] Step a: Same as step 1 in Example 1;
[0069] Step b: Use a probe to transfer a pre-deposited 100nm thick gold film to the surface of a Cs2AgBiBr6 quantum dot film as the source and drain (aspect ratio of 0.8).
[0070] like Figure 9 and 10 The transfer curves shown indicate that the Cs2AgBiBr6 quantum dot field-effect transistor prepared in Example 3 exhibits good performance regardless of the p-mechanism (source-drain voltage V). D =-60V), or in n-mechanism (source-drain voltage V D No obvious field effect was observed at 60V.
[0071] Further evidence confirms that the perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor constructed by the method of this invention effectively achieves strong field effects and efficient charge transport properties.
[0072] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.
Claims
1. A perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor, characterized in that, It is a bottom-gate top-contact structure, including: a gate, an insulating layer, a photosensitive layer, an active layer, a source, and a drain. The gate, insulating layer, photosensitive layer, and active layer are arranged in parallel and connected vertically from bottom to top. The source and drain are arranged in parallel and connected to the upper surface of the active layer. The photosensitive layer is a Cs2AgBiBr6 quantum dot film, and the active layer is a pentacene single crystal. The pentacene single crystal is transferred to the upper surface of the photosensitive layer and serves as the active layer using a heat-release tape.
2. The perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor according to claim 1, characterized in that, The thickness of the photosensitive layer is 30~80 nm, and the thickness of the active layer is 50~120 nm.
3. The perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor according to claim 2, characterized in that, The source and drain are gold films with a thickness of 80~150 nm.
4. The method for fabricating a perovskite quantum dot / organic semiconductor single-crystal heterojunction transistor as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Prepare a gate covered with an insulating layer as a substrate, and cover the insulating layer with a Cs2AgBiBr6 quantum dot film as the photosensitive layer; Step 2: Transfer the pentacene single crystal to the upper surface of the photosensitive layer and use it as the active layer; Step 3: Set the source and drain on the active layer.
5. The preparation method according to claim 4, characterized in that, The pentacene single crystal was prepared by micro-sublimation under atmospheric conditions.
6. The preparation method according to claim 5, characterized in that, The micro-sublimation method is as follows: An upper substrate and a lower substrate located directly below the upper substrate are placed in a sealed environment. Pentylene powder is placed on the upper surface of the lower substrate. A silicon wafer covered with a silicon dioxide layer is fixed on the lower surface of the upper substrate with the silicon dioxide layer facing down. The lower substrate is heated to 255-270 °C and held for 8-12 minutes. The pentylene single crystal is formed on the surface of the silicon dioxide layer of the silicon wafer fixed under the upper substrate. The volume fraction of the sealed environment to the mass fraction of the pentylene powder is (0.5-0.8):(1-5), where the volume fraction is in cm³. 3 The unit for the mass fractions is mg.
7. The preparation method according to claim 6, characterized in that, In step 1, the method for coating the insulating layer with a Cs2AgBiBr6 quantum dot film is as follows: a solvent and Cs2AgBiBr6 quantum dots are mixed to obtain a Cs2AgBiBr6 quantum dot solution, the Cs2AgBiBr6 quantum dot solution is spin-coated onto the insulating layer, and annealing is performed to remove the solvent to obtain the Cs2AgBiBr6 quantum dot film.
8. The preparation method according to claim 7, characterized in that, The concentration of Cs2AgBiBr6 quantum dots in the Cs2AgBiBr6 quantum dot solution is 0.5~2.5 mg / mL.
9. The preparation method according to claim 8, characterized in that, The solvent is n-hexane, the spin coating speed is 1000~2000 r / min, the spin coating time is 45~90 s, the annealing temperature is 90~120 ℃, and the annealing time is 8~12 min.
10. The preparation method according to claim 9, characterized in that, The preparation method of the Cs2AgBiBr6 quantum dots is as follows: Cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid and n-octane are mixed evenly and heated at 90~120 ℃ for 50~80 min to obtain a mixture. Under stirring conditions, trimethylsilicon bromide is injected into the mixture. After the reaction is completed for 3~5 s, the system temperature is lowered to 0~5 ℃ and centrifuged. The obtained solid is Cs2AgBiBr6 quantum dots.
11. The preparation method according to claim 10, characterized in that, The ratio of the molar amounts of cesium acetate, bismuth acetate, silver acetate, oleylamine, oleic acid, n-octane, and trimethylsilicon bromide is (0.69~0.72):(0.48~0.52):(0.48~0.52):(1.8~2.2):(5.8~6.2):(19~21):(0.83~0.85), where the molar amounts are in mmol and the volume parts are in mL.