A method of fabricating a flexible photodetector
By fabricating a flexible bismuth sulfide nanosheet photodetector based on a deionized water solid electrolyte, the problem of large size and easy leakage of traditional photodetectors has been solved, achieving fast response, high current response and good mechanical flexibility, thus broadening its application prospects in flexible electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIANGTAN UNIV
- Filing Date
- 2023-02-11
- Publication Date
- 2026-07-28
AI Technical Summary
Traditional photoelectrochemical photodetectors, which use electrolytes as conductive media, suffer from drawbacks such as large size and easy leakage, limiting their application in flexible electronic devices.
A flexible bismuth oxysulfate nanosheet photodetector based on deionized water solid electrolyte is used. The preparation process involves mixing bismuth oxysulfate powder with polyvinyl alcohol to form a semi-transparent solid electrolyte. Working electrodes and reference electrodes are then fabricated on a PET film, and deionized water is used as the conductive medium to form a flexible photodetector.
It achieves fast response speed and high current response of flexible photodetectors, with good mechanical flexibility and stability, safety and environmental friendliness, simple manufacturing process, low cost, and is suitable for large-scale production.
Smart Images
Figure CN116593545B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoelectrochemical detection, specifically relating to a method for preparing a flexible bismuth sulfide nanosheet photodetector based on a deionized water solid electrolyte. Background Technology
[0002] Photodetectors, as sensors that convert light signals into receivable and processable electrical signals, are widely used in fields such as solar power generation, biomedicine, environmental monitoring, and remote control. Photoelectrochemical photodetectors are a novel type of photodetector whose working principle is based on the semiconductor-liquid contact mechanism. When a semiconductor comes into contact with a liquid, electrons and holes separate under the influence of the built-in electric field formed at the interface. Therefore, photoelectrochemical photodetectors can generate high current response and fast response speed without an external power supply, and can even operate stably in emergency situations such as power outages, greatly expanding their applications in real-world scenarios.
[0003] However, traditional photoelectrochemical photodetectors, which use electrolytes as the conductive medium, suffer from drawbacks such as large size and susceptibility to leakage, limiting their practical applications. Flexible technology, as a crucial development in modern science and technology, holds significant application prospects in fields such as biomedicine, information, and energy. In recent years, flexible wearable electronic devices have attracted widespread attention from researchers across various fields due to their portability and wearability. To meet the diverse application needs of these flexible electronic devices, photodetectors require fast light response speeds and high current responses to satisfy the rapidly evolving demands of flexible integrated circuit technology and manufacturing processes. Summary of the Invention
[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for preparing a flexible bismuth sulfide nanosheet photodetector based on a deionized water solid electrolyte.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] This invention provides a method for preparing a flexible bismuth sulfide nanosheet photodetector based on a deionized water solid electrolyte, comprising the following steps:
[0007] 1) Pour 100 mg of bismuth nitrate pentahydrate and 20 ml of deionized water into beaker A. Place beaker A under sonication to make the mixture more homogeneous until it is completely dissolved. Let beaker A stand for a period of time to ensure that no precipitate has formed.
[0008] 2) Mix 1 ml of hydrazine hydrate and 12.7 mg of thiourea and place them in beaker B. Sonicate the mixture for 2 h to ensure thorough mixing.
[0009] 3) Take the solution in beaker A obtained in step 1) and mix it with the solution in beaker B obtained in step 2). Add 120 mg of potassium hydroxide and 320 mg of sodium hydroxide, and stir continuously for 30 min. Let it stand overnight. Then collect the dark precipitate, wash it with water and alcohol at least 5 times, and finally dry it in a vacuum drying oven at 70 °C to obtain pure bismuth oxysulfur powder.
[0010] 4) Add 1.5 g of polyvinyl alcohol (PVA) to 16 ml of deionized water and stir magnetically for 20 min at 95 ℃ to obtain a uniform semi-transparent solid electrolyte.
[0011] 5) The PET film was soaked and cleaned with acetone and anhydrous ethanol for 10-20 minutes respectively and then dried to obtain a pure sample.
[0012] 6) Take 1 mg of the bismuth-oxy-sulfur sample obtained in step 3) and add it to 1 ml of anhydrous ethanol, and treat it with ultrasound for 2 h. Use a dropper to drop the prepared suspension onto a PET substrate, and finally dry the substrate in a vacuum drying oven at 60 ℃ for 8 h to obtain the working electrode of the flexible photodetector.
[0013] 7) Mix 1 mg of carbon black with 1 ml of NMP (N-methyl-2-pyrrolidone), and drop 200 μl of the carbon black solution onto a PET substrate. Dry the substrate in a vacuum drying oven at 60 °C for 8 h to obtain the reference electrode for the flexible photodetector;
[0014] 8) Take the solid electrolyte obtained in step 4) and uniformly coat it onto the electrode obtained in step 6). Allow the solid electrolyte to solidify at room temperature. Then take the reference electrode of the flexible photodetector obtained in step 7) and stack the two electrodes of the flexible device together. Allow it to stand and dry at room temperature for 20-30 hours to obtain the flexible photodetector.
[0015] 9) The flexible photodetector obtained in step 8) was subjected to photoelectric performance testing using an electrochemical workstation. The linear current-voltage characteristic (LSV) scan rate was 10 mV / s. The current-time (it) curve period was 20 s, and the test light source was a 350 W xenon lamp.
[0016] 10) Repeat the experiment of voltage testing of flexible photodetector in step 9) by changing the parameters. The changed parameters are: voltage increases from 0 V to 0.9 V, light irradiance increases from 55 mW / cm² to 95 mW / cm², cyclic testing is performed for 1000 s, and bending angle increases from 0° to 60°.
[0017] According to a preferred embodiment of the present invention, in step 1), the ultrasonic treatment time is 2 hours.
[0018] According to a preferred embodiment of the present invention, in step 2), the mass of thiourea is 12.7 mg and the volume of hydrazine hydrate is 1 ml.
[0019] According to a preferred embodiment of the present invention, in step 3), the vacuum drying time is 24 h.
[0020] According to a preferred embodiment of the present invention, in step 4), the mass of the sample is 1.5 mg, the volume of deionized water is 16 ml, the temperature required for magnetic stirring is 95°C, and the magnetic stirring time is 20 min.
[0021] According to a preferred embodiment of the present invention, in step 5), the immersion and cleaning with acetone and anhydrous ethanol is performed for 15 minutes.
[0022] According to a preferred embodiment of the present invention, in step 6), the mass of the bismuth oxide sulfur sample is 1 mg, the volume of anhydrous ethanol is 1 ml, the drying temperature is 60 °C, and the drying time is 8 h.
[0023] According to a preferred embodiment of the present invention, in step 7), the volume of the spin-coated carbon black solution is 0.2 ml, the concentration is 1 mg / ml, the drying temperature is 60 ℃, and the drying time is 8 h.
[0024] According to a preferred embodiment of the present invention, in step 8), the amount of solid electrolyte coated on each electrode is 2 ml, and the drying time at room temperature is 4 h.
[0025] According to a preferred embodiment of the present invention, in step 9), the scan rate of the linear current-voltage characteristic (LSV) test is 10 mV / s. The period of the current-time relationship (it) curve is 20 s, and the test light source is a 350 W xenon lamp.
[0026] According to a preferred embodiment of the present invention, in step 10), the voltage is tested at intervals of 0.1 V, the light irradiance is tested at intervals of 10 mW / cm², and the bending angle is tested at intervals of 30°.
[0027] All equipment and raw materials used in the method of this invention are commercially available products. Based on the above technical solution, this invention has the following advantages:
[0028] (1) The present invention has found through research that the flexible bismuth sulfide nanosheet photodetector based on deionized water solid electrolyte exhibits good photoresponse characteristics, stability and mechanical flexibility.
[0029] (2) This discovery found that this bismuth-oxygen-sulfur nanosheet flexible detector is significantly safer and more environmentally friendly than traditional detectors. Moreover, the manufacturing process is simple and the cost is low, which can be used for large-scale preparation and further broadens the application prospects of the device. Attached Figure Description
[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below:
[0031] Figure 1 This is a schematic diagram of the flexible photodetector structure involved in this invention.
[0032] Figure 2 The figure shows the response time curve of the flexible photodetector based on bismuth oxysulfate nanosheets. As can be seen from the figure, the rise time and fall time of the photodetector are 0.045 s and 0.13 s, respectively, indicating a fast response speed. The bismuth oxysulfate photodetector exhibits good photoresponse characteristics at 0 V, and its photocurrent density is 0.55 μA / cm² when the optical power is 75 mW / cm², demonstrating a relatively high photocurrent density.
[0033] Figure 3 This section presents the photocurrent, photoresponse, and optical power density curves of a flexible photodetector fabricated based on bismuth oxysulfate nanosheets. It shows the rise and fall times of the solid-state electrolyte-based photodetector at 75 mW / cm² without any applied bias. By comparing the response times of conventional and flexible photodetectors, it can be seen that this detector exhibits an ultrafast response rate.
[0034] Figure 4 The figures show the time-current curves of flexible photodetectors fabricated based on bismuth oxysulfate nanosheets under different bias voltages.
[0035] Figure 5 The figure shows the time-current curves of flexible photodetectors based on bismuth oxysulfate nanosheets under different light intensities. As can be seen from the figure, the photocurrent density is 0.5–1 μA / cm² under forward light intensity, representing an approximately two-fold increase.
[0036] Figure 6 The figure shows the time-current curves of the flexible photodetector based on bismuth oxysulfate nanosheets after 1000 s of cyclic switching. As can be seen from the figure, after 1000 s of cyclic switching, the photocurrent decreased slightly by 8% compared to the initial state, demonstrating excellent stability.
[0037] Figure 7The figure shows the time-current curves of a flexible photodetector based on bismuth oxysulfate nanosheets at different bending angles. As can be seen from the figure, when the bending angle is 30°, the photocurrent density is approximately 91% of the original state, while when the bending angle is 60°, the photocurrent density is approximately 76% of the original state. This is likely due to small cracks formed during the bending process. The results indicate that bismuth oxysulfate nanosheets possess good mechanical flexibility. Detailed Implementation
[0038] Example 1
[0039] A method for preparing a flexible photodetector based on a deionized water solid electrolyte bismuth sulfide nanosheet, wherein the flexible photodetector is a photoelectrochemical photodetector using a deionized water solid electrolyte as the conductive medium, comprising the following steps:
[0040] 1) Pour 100 mg of bismuth nitrate pentahydrate and 20 ml of deionized water into beaker A. Place beaker A under sonication to make the mixture more homogeneous until it is completely dissolved. Let beaker A stand for a period of time to ensure that no precipitate has formed.
[0041] 2) Mix 1 ml of hydrazine hydrate and 12.7 mg of thiourea and place them in beaker B. Sonicate the mixture for 2 h to ensure thorough mixing.
[0042] 3) Take the solution in beaker A obtained in step 1) and mix it with the solution in beaker B obtained in step 2). Add 120 mg of potassium hydroxide and 320 mg of sodium hydroxide, and stir continuously for 30 min. Let it stand overnight. Then collect the dark precipitate, wash it with water and alcohol at least 5 times, and finally dry it in a vacuum drying oven at 70°C to obtain pure bismuth oxysulfur powder.
[0043] 4) Add 1.5 g of polyvinyl alcohol (PVA) to 16 ml of deionized water and stir magnetically for 20 min at 95°C to obtain a uniform, semi-transparent solid electrolyte.
[0044] 5) The PET film was soaked and cleaned with acetone and anhydrous ethanol for 10-20 minutes respectively and then dried to obtain a pure sample.
[0045] 6) Take 1 mg of the bismuth-oxy-sulfur sample obtained in step 3) and add it to 1 ml of anhydrous ethanol, and treat it with ultrasound for 2 h. Use a dropper to drop the prepared suspension onto a PET substrate, and finally dry the substrate in a vacuum drying oven at 60 °C for 8 h to obtain the working electrode of the flexible photodetector.
[0046] 7) Mix 1 mg of carbon black with 1 ml of NMP (N-methyl-2-pyrrolidone), and drop 200 μl of the carbon black solution onto a PET substrate. Dry the substrate in a vacuum drying oven at 60 °C for 8 h to obtain the reference electrode for the flexible photodetector;
[0047] 8) Take the solid electrolyte obtained in step 4) and uniformly coat it onto the electrode obtained in step 6). Allow the solid electrolyte to solidify at room temperature. Then take the reference electrode of the flexible photodetector obtained in step 7) and stack the two electrodes of the flexible device together. Allow it to stand and dry at room temperature for 20-30 hours to obtain the flexible photodetector.
[0048] 9) The flexible photodetector obtained in step 8) was subjected to photoelectric performance testing using an electrochemical workstation. The linear current-voltage characteristic (LSV) scan rate was 10 mV / s. The current-time (it) curve period was 20 s, and the test light source was a 350 W xenon lamp.
[0049] 10) Repeat the experiment of voltage testing of flexible photodetector performed in step 9) by changing the parameters. The changed parameters are: voltage increases from 0 V to 0.9 V, light irradiance increases from 55 mW / cm² to 95 mW / cm², cyclic testing is performed for 1000 s, and bending angle increases from 0° to 60°.
Claims
1. A method for fabricating a flexible photodetector, wherein the flexible photodetector is a flexible bismuth sulfide nanosheet photodetector based on a deionized water solid electrolyte, characterized in that... The steps are as follows: 1) Pour 100 mg of bismuth nitrate pentahydrate and 20 ml of deionized water into beaker A. Place beaker A under sonication to make the mixture inside more homogeneous until it is completely dissolved. Let beaker A stand for a period of time to confirm that no precipitate has formed. 2) Mix 1 ml of hydrazine hydrate and 12.7 mg of thiourea and place them in beaker B. Sonicate the mixture for 2 h to ensure thorough mixing. 3) Take the solution in beaker A obtained in step 1) and mix it with the solution in beaker B obtained in step 2). Add 120 mg of potassium hydroxide and 320 mg of sodium hydroxide and stir continuously for 30 min. Let it stand overnight. Then collect the dark precipitate, wash it with water and alcohol at least 5 times, and finally dry it in a vacuum drying oven at 70 °C to obtain pure bismuth oxysulfur powder. 4) 1.5 g of polyvinyl alcohol (PVA) was added to 16 ml of deionized water and magnetically stirred at 95 °C for 20 min to obtain a uniform, semi-transparent solid electrolyte. 5) The PET film was soaked and cleaned with acetone and anhydrous ethanol for 10-20 minutes respectively and then dried to obtain a pure sample. 6) Take 1 mg of the bismuth-oxy-sulfur sample obtained in step 3) and add it to 1 ml of anhydrous ethanol. Then, use an ultrasonic treatment for 2 h. Use a dropper to drop the prepared suspension onto the PET substrate. Finally, dry the substrate in a vacuum drying oven at 60 ℃ for 8 h to obtain the working electrode of the flexible photodetector. 7) Mix 1 mg of carbon black with 1 ml of NMP (N-methyl-2-pyrrolidone), and drop 200 μl of carbon black solution onto a PET substrate. Dry the substrate in a vacuum drying oven at 60 °C for 8 h to obtain the reference electrode of the flexible photodetector. 8) Take the solid electrolyte obtained in step 4) and uniformly coat it onto the electrode obtained in step 6). Allow the solid electrolyte to solidify at room temperature. Then take the reference electrode of the flexible photodetector obtained in step 7) and stack the two electrodes of the flexible device together. Allow it to stand and dry at room temperature for 20-30 hours to obtain the flexible photodetector. 9) Perform photoelectric performance testing on the flexible photodetector obtained in step 8). The testing system is an electrochemical workstation. During the test, the scan rate of the linear current-voltage characteristic (LSV) test is 10 mV / s, the period of the current-time relationship (it) curve is 20s, and the test light source is a 350 W xenon lamp. 10) Repeat the experiment of voltage test of flexible photodetector in step 9) by changing the parameters. The parameters are: voltage increases from 0 V to 0.9 V, light irradiance increases from 55 mW / cm² to 95 mW / cm², cyclic test is performed for 1000 s, and bending angle increases from 0° to 60°.
2. The method for fabricating a flexible photodetector according to claim 1, characterized in that, In step 1), the ultrasonic treatment time is 2 hours.
3. The method for fabricating a flexible photodetector according to claim 1, characterized in that, In step 5), the soaking and cleaning time for acetone and anhydrous ethanol is 15 min each.
4. The method for fabricating a flexible photodetector according to claim 1, characterized in that, In step 7), the carbon black solution spin-coated onto the PET substrate has a volume of 0.2 ml and a concentration of 1 mg / ml.
5. The method for fabricating a flexible photodetector according to claim 1, characterized in that, In step 8), 2 ml of solid electrolyte is coated on each electrode, and the drying time is 4 h.