A composite conductive thin film electrode for ultraviolet optoelectronic devices and a method of manufacturing the same

Abstract

A transparent composite conductive film electrode for ultraviolet photoelectric devices is composed of an electrode bottom layer and a top layer on the surface of the electrode bottom layer, the electrode bottom layer is a silver nanowire film, and the top layer is a pyrolysis zirconium acetylacetonate protective layer, the pyrolysis zirconium acetylacetonate protective layer is a precursor solution prepared by taking zirconium acetylacetonate as a solute and taking ethanol and dimethylformamide as a composite solvent, the precursor solution is deposited on the surface of the silver nanowire film through atomization pyrolysis, and finally vacuum annealing is carried out to obtain the pyrolysis zirconium acetylacetonate protective layer which is decomposed into a complex component. By dissolving zirconium acetylacetonate in a composite solvent composed of DMF and ethanol, a transparent conductive film is formed on the surface of the Ag nanowire film through spray pyrolysis deposition, the light transmittance of the conductive film under 310 nm ultraviolet light reaches 97.7% of the Ag nanowire film without a protective layer, and the composite electrode effectively improves the charge collection capacity and transmission stability of the electrode.

Description

Technical Field

[0001] This invention relates to the field of conductive thin film preparation technology, specifically to a composite conductive thin film electrode for ultraviolet optoelectronic devices and its preparation method. Background Technology

[0002] Sensors, also called detectors or sensors, are instruments that collect, detect, and record electromagnetic radiation information from objects on the ground. Structurally, all types of sensors consist of a collector, a detector, a processor, and an output device. Therefore, sensors are often called detectors, as a detector is a type of sensor. Detectors can be classified according to their detection wavelength, such as ultraviolet detectors, visible light detectors, and infrared detectors. Ultraviolet optoelectronic devices include ultraviolet photodetectors and ultraviolet light-emitting diodes (LEDs). Due to their high sensitivity, high resolution, and fast response, ultraviolet photodetector thin-film diode detectors have broad application prospects in fields such as medical imaging, missile identification and tracking, communications, and environmental and biochemical detection. Ultraviolet optoelectronic devices are generally composed of a bottom electrode, a p-type semiconductor thin film, an n-type semiconductor thin film, and a transparent conductive thin film, deposited and stacked sequentially. Ultraviolet optoelectronic devices have special requirements for the transparent conductive thin film, which needs to have high ultraviolet transmittance, excellent physicochemical stability, and resistance to ultraviolet damage; these are the key materials for ultraviolet optoelectronic devices.

[0003] Existing transparent conductive films such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and aluminum-doped zinc oxide (AZO) have low transmittance to short-wave ultraviolet light. For example, the average transmittance of ITO in the UVB range (280-320 nm) is about 25%. Therefore, optical devices based on ITO windows have very low photoelectric conversion efficiency in the UVB region, severely limiting their application. Thus, their use as ultraviolet window electrodes is difficult for deep ultraviolet detection. Existing technologies have reported the use of silver nanowires (AgNws) as window electrodes for ultraviolet optoelectronic devices; however, the contact between the electrode and other films is a loose physical contact, resulting in low charge collection efficiency and low quantum efficiency. Furthermore, nanomaterials have poor chemical stability and poor interfacial contact, especially in photodetectors, leading to poor signal stability, high noise current, and unfavorable signal amplification and processing. In addition, external environmental influences cause changes in film resistance, resulting in poor signal repeatability and a faster decline in the lifespan of some devices. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide an ultraviolet window electrode for ultraviolet optoelectronic devices. When used in ultraviolet photoelectric thin-film detectors, this electrode significantly improves responsivity, signal stability, and lifespan, while reducing noise density, which is beneficial for subsequent signal amplification and processing.

[0005] Another objective of this invention is to provide a method for preparing the aforementioned ultraviolet window electrode. The ultraviolet window electrode prepared by this method has high transparency, excellent conductivity, and strong adhesion and resistance to water and oxygen on the surface of ultraviolet optoelectronic materials.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A transparent composite conductive thin-film electrode for optoelectronic devices is characterized in that: the transparent conductive film is a silver nanowire film protected by pyrolytic zirconium acetylacetonate, specifically composed of a bottom electrode layer and a top layer on its surface. The bottom electrode layer is a silver nanowire film, and the top layer is pyrolytic zirconium acetylacetonate. The pyrolytic zirconium acetylacetonate is a precursor solution prepared by using zirconium acetylacetonate as a solute and ethanol and dimethylformamide as a composite solvent. It is deposited on the surface of the silver nanowire film by atomization pyrolysis, and finally vacuum annealed to obtain pyrolytic zirconium acetylacetonate decomposed into a complex composition.

[0008] Furthermore, in the composite solvent, the volume ratio of ethanol to dimethylformamide is 3:1 to 5:1.

[0009] Furthermore, the concentration of the mixed solution is 0.006~0.05 mol / L.

[0010] Furthermore, the pyrolysis deposition temperature of pyrolyzanthione is 110~140 ℃, and the deposition rate is 2~10 nm / min.

[0011] Furthermore, the atomizer for spray pyrolysis uses a 1.4 MHz ultrasonic atomizing head, the diameter of the mist guide tube outlet is 20 mm, the distance between the mist guide tube outlet and the sample is 10~20 mm, the carrier gas is nitrogen, the rate is 6~10 L / min, and the atomization rate is about 3~15 mL / min.

[0012] Furthermore, the vacuum annealing is performed at 140~200 °C for 0.5~24 h, preferably using a vacuum tube furnace, in order to help improve the degree of decomposition of zirconium acetylacetonate.

[0013] A method for preparing a composite conductive thin film electrode is characterized in that: a precursor solution is prepared by using zirconium acetylacetonate as a raw material, and the precursor solution is sprayed and pyrolyzed to deposit on the surface of a silver nanowire thin film to form a pyrolyzonium acetylacetonate protective layer. The solvent of the precursor solution is ethanol and dimethylformamide in a volume ratio of 3:1 to 5:1, and the concentration of the precursor solution is 0.006 to 0.05 mol / L.

[0014] Furthermore, the atomizer for the spray pyrolysis uses a 1.4 MHz ultrasonic atomizing head, the diameter of the mist guide tube outlet is 20 mm, the distance between the mist guide tube outlet and the sample is 10~20 mm, the carrier gas is nitrogen, the inlet rate is 6~10 L / min, and the atomization rate is about 3~15 mL / min.

[0015] Furthermore, the pyrolysis deposition temperature is 110~140 ℃, the deposition rate is 2~10 nm / min, and the deposition thickness is 20~100 nm.

[0016] Furthermore, after deposition, annealing is performed with an annealing vacuum of less than 5 Pa, an annealing temperature of 140~200℃, and an annealing time of 0.5~24 h.

[0017] When silver nanowire (AgNws) thin films are used as window electrodes in ultraviolet optoelectronic devices, the charge collection efficiency is low, resulting in low quantum efficiency. Furthermore, nanomaterials exhibit poor chemical stability, particularly in photodetectors, leading to poor signal stability, high noise current, and unfavorable conditions for subsequent signal amplification and processing.

[0018] In this invention, zirconium acetylacetonate is used as a raw material, dissolved in a composite solvent composed of ethanol and dimethylformamide to form a precursor solution. This precursor solution is then deposited onto the surface of a silver nanowire thin film via spray pyrolysis to form a protective layer. During the pyrolysis deposition process, the deposition temperature is adjusted to 110-140℃ to achieve the volatilization, initial pyrolysis, and solidification of the zirconium acetylacetonate solution, resulting in the initial formation of the protective layer and providing protection for the AgNws. Subsequently, vacuum annealing at a higher temperature of 140-200℃ further pyrolyzes the zirconium acetylacetonate. Due to the initial protective effect of the precursor layer, the higher annealing temperature does not damage the AgNws, thus improving the chemical stability and optical transmittance of the transparent conductive film.

[0019] In this invention, DMF and ethanol are used in a specific ratio to form a precursor solution. During the deposition and annealing processes, this precursor solution has a significant impact on the composition and grain structure of the final pyrolyzed zirconium acetylacetonate. Under specific pyrolysis deposition and annealing conditions, the different volatilization characteristics of DMF and ethanol at different temperatures lead to a complex decomposition and crystallization process in the pyrolysis of zirconium acetylacetonate. This results in a protective layer with a unique grain structure between zirconium acetylacetonate and zirconium oxide. This protective layer film adheres to the AgNws film, forming a dense structure with uniform distribution of components. This effectively improves the signal stability of the transparent conductive film while reducing the noise current density.

[0020] A method for preparing a composite conductive thin film electrode, characterized by comprising the following steps:

[0021] S1. Preparation of AgNws thin films

[0022] A silver nanowire film with a thickness of 30-40 nm and a sheet resistance of 10-12 Ω / sq was prepared by depositing a thin film on the substrate surface using silver nanowire ink with a solid content of 8-12 g / L and a diameter of 25-35 nm, and then annealing it at 100 °C for 10 min.

[0023] S2. Preparation of the mixture

[0024] Zirconium acetylacetonate was added to a composite solvent composed of ethanol and dimethylformamide to prepare a mixed solution with a concentration of 0.006~0.05 mol / L. The volume ratio of ethanol to dimethylformamide in the composite solvent was 3:1~5:1.

[0025] S3. Spray pyrolysis deposition top layer

[0026] The AgNws film was heated to 110-140 °C. The mixture prepared in step S1 was placed in an atomizing cup and atomized using a 1.4 MHz ultrasonic atomizing head. The atomizing head directed the atomizing gas to the surface of the AgNws film through a mist guide tube. The diameter of the mist guide tube outlet was 20 mm, and the distance between the outlet and the sample was 10-20 mm. Nitrogen was used as the carrier gas at a rate of 6-10 L / min, and the atomization rate was approximately 3-15 mL / min. The deposition rate of pyrolyzonium acetylacetonate was 2-10 nm / min, and the deposition thickness was 20-100 nm.

[0027] S4. Annealing treatment

[0028] The thin film was annealed in a vacuum tube furnace with a vacuum level below 5 Pa, an annealing temperature of 140~200 ℃, and an annealing time of 0.5~24 h.

[0029] The present invention has the following technical effects:

[0030] This invention dissolves zirconium acetylacetonate in a composite solvent composed of DMF and ethanol, and deposits it onto the surface of an Ag nanowire thin film via spray pyrolysis. After pyrolysis, a multi-component complex protective layer is formed, which is intermediate between zirconium acetylacetonate and zirconium oxide. This solves the problems of low adhesion and loose interfacial bonding between the film prepared by AgNws and the detection material in the prior art, optimizes the interfacial bonding, and ensures excellent light transmittance. The transmittance of 310nm ultraviolet light reaches 97.7% of that of the Ag nanowire thin film without a protective layer. The resulting composite electrode effectively improves the charge collection ability and transmission stability of the electrode. Attached Figure Description

[0031] Figure 1 : Schematic diagram of the ultrasonic spray pyrolysis device for depositing pyrolyzonium acetylacetonate according to the present invention.

[0032] Figure 2Thermal analysis diagram of zirconium acetylacetonate.

[0033] Figure 3 X-ray photoelectron spectroscopy (XPS) of pyrolytic zirconium acetylacetonate prepared at different temperatures.

[0034] Figure 4 Comparison of scanning electron microscope images of the transparent conductive film and the unprotected AgNws film for ultraviolet optoelectronic devices prepared in Example 1 of this invention.

[0035] Figure 5 Transmittance test diagrams of the transparent conductive films for ultraviolet optoelectronic devices prepared in Example 1 and Comparative Example 1 of this invention.

[0036] Figure 6 Comparison of the transparent conductive film for ultraviolet optoelectronic devices prepared in Example 1 of this invention with unprotected AgNws film tape.

[0037] Figure 7 Comparison of the IT response characteristic curves of detectors prepared in Example 2 of this invention and the control group without protective layer to ultraviolet light of different wavelengths.

[0038] Figure 8 Comparison of photocurrent changes over time between the detector prepared in Example 2 of this invention and the control detector without a protective layer.

[0039] Figure 9 Comparison of noise current density between the detector prepared in Example 2 of this invention and the control detector without a protective layer.

[0040] Figure 10 Comparison of the responsivity of detectors with different protective layers prepared in Example 2 and Comparative Example 2 to 310nm ultraviolet light. Detailed Implementation

[0041] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0042] Example 1

[0043] A method for preparing a transparent composite conductive thin film electrode includes the following steps:

[0044] S1. Preparation of AgNws thin films

[0045] A silver nanowire film with a thickness of 30 nm and a sheet resistance of 10 Ω / sq was prepared by depositing a thin film on the substrate surface using silver nanowire ink with a solid content of 10 g / L and a diameter of 25~35 nm, and then annealing it at 100 ℃ for 10 min.

[0046] S2. Preparation of the mixture

[0047] Zirconium acetylacetonate was added to a composite solvent composed of ethanol and dimethylformamide to prepare a mixed solution with a concentration of 0.01 mol / L. The volume ratio of ethanol to dimethylformamide in the composite solvent was 4:1.

[0048] S3. Spray pyrolysis deposition top layer

[0049] The AgNws film was heated to 120 °C. The mixture prepared in step S1 was placed in an atomizing cup and atomized using a 1.4 MHz ultrasonic atomizing head. The atomizing tube directed the atomization to the surface of the AgNws film. The diameter of the atomizing tube outlet was 20 mm and the distance from the outlet to the sample was 15 mm. Nitrogen was used as the carrier gas at a rate of 8 L / min, and the atomization rate was 12 mL / min. The deposition rate of pyrolyzonium acetylacetonate was 5 nm / min, and the deposition thickness was 50 nm.

[0050] S4. Annealing treatment

[0051] The thin film was annealed in a vacuum tube furnace with a vacuum level below 5 Pa, an annealing temperature of 160 °C, and an annealing time of 24 h.

[0052] Figure 1 This is a schematic diagram of the ultrasonic spray pyrolysis apparatus for depositing pyrolyzonium acetylacetonate according to the present invention.

[0053] Figure 2 The thermal analysis diagram of zirconium acetylacetonate shows that the weight loss starting at 101℃ represents the first stage of thermal decomposition, and the second stage begins at 264℃. Before 500℃, zirconium acetylacetonate is not completely decomposed into zirconium oxide. However, the pyrolysis and annealing temperatures of zirconium acetylacetonate in this invention are 110-140℃ and 140-200℃, respectively, indicating that the prepared protective layer is not simply zirconium oxide or zirconium acetylacetonate, but a complex system composed of multiple decomposition components.

[0054] Figure 3X-ray photoelectron spectroscopy (XPS) was performed on pyrolyzed zirconium acetylacetonate prepared at different temperatures. The peaks with higher binding energies were identified as O1s XPS peaks from the acetylacetonate group (acac), while the peaks with lower binding energies were identified as O1s XPS peaks from zirconium oxide. As the pyrolysis temperature increased from 120 °C to 200 °C, the O1s XPS peaks from zirconium oxide gradually increased in intensity, but the O1s XPS peaks from the acetylacetonate group (acac) remained dominant, further confirming that the protective layer is an intermediate product with a composition between zirconium acetylacetonate and zirconium oxide.

[0055] Figure 4 Scanning electron microscope (SEM) images of the AgNws transparent conductive thin film with pyrolytic zirconium acetylacetonate protective layer prepared in Example 1 of this invention are shown. In the images, a represents an unprotected AgNws thin film electrode, and b represents an ultraviolet window electrode with the pyrolytic zirconium acetylacetonate protective layer deposited on its surface. As can be seen from the images, the AgNws are completely encased within the pyrolytic zirconium acetylacetonate protective layer, and the surface is dense, with no cracks or pores observed.

[0056] Comparative Example 1

[0057] To demonstrate the advantages of pyrolytic zirconium acetylacetonate, hafnium acetylacetonate, which has similar properties, was used to replace zirconium acetylacetonate in the precursor solution. Pyrolytic hafnium acetylacetonate-protected AgNws films of different thicknesses were prepared on quartz glass and compared with AgNws films of different thicknesses prepared by the method in Example 1.

[0058] The ultraviolet light transmittance of the conductive films prepared in Example 1 and Comparative Example 1 was measured, and the results are as follows: Figure 5 As shown in the figure, pyrolytic hafnium acetylacetonate exhibits a distinct absorption peak in the 240-330 nm range. When the thickness is low, the impact on the transmittance of the transparent conductive film is minimal; however, the effect becomes significant when the thickness of the pyrolytic hafnium acetylacetonate is substantial. For example, when the thickness of the pyrolytic hafnium acetylacetonate increases from 20 nm to 60 nm, the transmittance of the transparent conductive film at 310 nm decreases from 64% to 30%, resulting in a significant deterioration in device performance. In the AgNws thin film protected by pyrolytic zirconium acetylacetonate, the 20 nm thick transparent conductive film (green) exhibits good transmittance across the entire ultraviolet region (85% transmittance at 310 nm), approaching that of the unprotected AgNws film (87% transmittance at 310 nm). With increasing thickness of the pyrolytic zirconium acetylacetonate protective layer, the ultraviolet transmittance decreases slightly, but not significantly. For example, when the thickness of the pyrolytic zirconium acetylacetonate is 60 nm, the transmittance of the transparent conductive film only decreases from 85% to 82%, having little impact on device performance. This demonstrates that the protective layer coverage has little effect on the ultraviolet transmittance of the electrode.

[0059] Figure 6The results of adhesive tape tests on pyrolyzonium acetylacetonate-protected AgNws transparent conductive films and unprotected AgNws films are presented. The pyrolyzonium acetylacetonate-protected AgNws film did not detach from the substrate, and its sheet resistance showed no significant change, indicating that the pyrolyzonium acetylacetonate-protected AgNws transparent conductive film has good adhesion strength to the UV environment, while the unprotected AgNws film is very easily detached by the adhesive tape. Furthermore, the pyrolyzonium acetylacetonate-protected AgNws transparent conductive film does not absorb moisture or deliquesce in air, exhibiting good environmental stability. This suggests that pyrolyzonium acetylacetonate-protected AgNws transparent conductive film can improve the usability of UV optoelectronic devices.

[0060] Example 2

[0061] The above preparation method is applied to an ultraviolet photodiode detector:

[0062] With a size of 2×3 cm 2 An ITO glass substrate with a sheet resistance of 6Ω was used, with one side covered by a small area of ​​polyimide high-temperature resistant tape. TiO2 precursor solution was spin-coated onto the ITO glass, and then annealed at 460 °C for 30 min to obtain a TiO2 film with a thickness of 20 nm. Then, Bi2O3 precursor solution was spin-coated onto the surface of the TiO2 film, and after spin-coating, it was annealed at 450 °C for 30 min to prepare a Bi2O3 film with a thickness of about 40 nm. Finally, NiO precursor solution was spin-coated onto the surface of the Bi2O3 film, and annealed at 400 °C for 20 min to prepare a NiO film with a thickness of 20 nm.

[0063] Following the method in Example 1, a transparent conductive film of AgNws protected by pyrolytic zirconium acetylacetonate was prepared on the surface of a substrate deposited with ITO / TiO2 / Bi2O3 / NiO. Finally, the polyimide high-temperature resistant tape was removed, and electrode leads were fabricated using silver paste in the electrode film and the ITO blank areas to obtain a complete ultraviolet photodiode detector.

[0064] Figure 7 This document compares the it response characteristics of detectors prepared in Example 1 of this invention and a control group using an AgNws conductive film protected by a zirconium acetylacetonate layer to different wavelengths of ultraviolet light. Compared to a simple AgNws electrode, the AgNws transparent conductive film protected by pyrolytic zirconium acetylacetonate layer exhibits varying degrees of improved detection performance in the 254-365 nm wavelength range, for example, at a power density of 5 μW / cm². -2Under 254 nm ultraviolet light illumination, the detector photocurrent of the AgNws transparent conductive film protected by pyrolytic zirconium acetylacetonate was 0.84 μA, higher than the 0.65 μA of the detector with a simple AgNws electrode. This is because pyrolytic zirconium acetylacetonate increases the bonding between the AgNws in the pyrolytic zirconium acetylacetonate protective layer and the detector film surface, reducing the contact resistance between AgNws and NiO. In contrast, simple AgNws adheres to the NiO surface through physical contact, resulting in weak adhesion and poor contact tightness, leading to reduced charge transport and collection efficiency.

[0065] Figure 8 This figure compares the photocurrent changes over time between the detector of this invention and a detector with an unprotected AgNws ultraviolet window electrode. As can be seen from the figure, the detector with the pyrolytic zirconium acetylacetonate-protected AgNws transparent conductive film maintained stable performance after 90 days of exposure to the environment. This was achieved at a power density of 5 μW / cm². -2 Under 254 nm ultraviolet light illumination, the photocurrent remained almost constant at 0.84-0.80 μA. However, the detector using a simple AgNws ultraviolet window electrode showed significant degradation due to the gradual oxidation of AgNws in the environment. Under the same conditions, the photocurrent rapidly decreased from 0.65 μA to 0.38 μA within one month, and further decreased to 0.26 μA after three months. Pyrolysis of zirconium acetylacetonate can also reduce the noise current of the ultraviolet detector. Figure 9 As can be seen from the data, using pyrolyzed zirconium acetylacetonate-protected AgNws as the window electrode, the detector's performance at 10... -3 The noise current density is significantly reduced in the Hz-50Hz frequency range, indicating that the detector has a better gain effect when amplifying signals.

[0066] Comparative Example 2

[0067] Following the preparation method in Example 2, the AgNws transparent conductive film was replaced with protection using pyrolytic hafnium acetylacetonate, and the effects of different thicknesses of pyrolytic hafnium acetylacetonate and pyrolytic zirconium acetylacetonate on the response performance of the ultraviolet detector were tested.

[0068] The results are as follows Figure 10 As shown, the device with an unprotected AgNWs transparent conductive film as the window has a responsivity of 0.135 AW at 254 nm. -1 With a protective layer thickness of 20 nm, the performance of the two devices is similar, showing a significant improvement compared to unprotected devices. However, when the thickness exceeds 30 nm, the device using a pyrolytic zirconium acetylacetonate-protected AgNWs transparent conductive film as the window electrode exhibits significantly higher responsivity than the device using a pyrolytic hafnium acetylacetonate-protected AgNWs transparent conductive film as the window electrode, with responsivity of 0.167 AW. -1and 0.148 AW -1 As the protective layer thickness increases, the performance difference widens. The thickness of the pyrolyzed hafnium acetylacetonate has a greater impact on the responsivity at 310 nm ultraviolet light. Devices using unprotected AgNWs transparent conductive films as windows exhibit a responsivity of 0.064 AW at 310 nm. -1 With a protective layer thickness of 20 nm, the device performance difference between AgNWs transparent conductive films protected by pyrolytic zirconium acetylacetonate and pyrolytic hafnium acetylacetonate as window electrodes is not significant, with responsivity of 0.088 AW, respectively. -1 and 0.082 AW -1 However, when the protective layer thickness is 80 nm, the responsivity of the device with the pyrolytic zirconium acetylacetonate-protected AgNWs transparent conductive film as the window and the device with the pyrolytic hafnium acetylacetonate-protected AgNWs transparent conductive film as the window to 310 nm ultraviolet light is 0.082 AW, respectively. -1 and 0.046 AW -1 This indicates that pyrolytic zirconium acetylacetonate is more advantageous as a protective layer for AgNWs at larger thicknesses, and is more conducive to improving the stability and repeatability of device performance in industrial production.

[0069] During the preparation process, the precursor mixtures prepared in different solvents had significant effects on electrode performance after forming a 50 nm thick protective layer on the surface of the AgNws thin film. The results are shown in Table 1.

[0070] Table 1:

[0071]

[0072] It can be seen that the conductive film with a protective layer prepared using DMF and ethanol as composite solvents showed almost no decrease in light transmittance in the 240-330 nm range after 90 days, while the light transmittance of the composite solvent groups consisting of ethanol alone and ethanol and ethylene glycol methyl ether showed a significant decrease. This was observed at a power density of 5 μW / cm². -2 Under these conditions, the photocurrent of the DMF and ethanol composite solvent group remained relatively stable after 90 days, while ethanol alone and the ethanol and ethylene glycol methyl ether groups showed significant attenuation. This demonstrates that different solvent choices have different effects on the structure and performance of the formed protective layer. The composite solvent of DMF and ethanol selected in this invention effectively improves the structural and performance stability of the film.

[0073] Example 3

[0074] A method for preparing a composite conductive thin film electrode includes the following steps:

[0075] S1. Preparation of AgNws thin films

[0076] A silver nanowire film with a thickness of 40 nm and a sheet resistance of 12 Ω / sq was prepared by depositing a thin film on the substrate surface using silver nanowire ink with a solid content of 8 g / L and a diameter of 25~35 nm, and then annealing it at 100 °C for 10 min.

[0077] S2. Preparation of the mixture

[0078] Zirconium acetylacetonate was added to a composite solvent composed of ethanol and dimethylformamide to prepare a mixed solution with a concentration of 0.05 mol / L. The volume ratio of ethanol to dimethylformamide in the composite solvent was 3:1.

[0079] S3. Spray pyrolysis deposition top layer

[0080] The AgNws film was heated to 140 °C. The mixture prepared in step S1 was placed in an atomizing cup and atomized using a 1.4 MHz ultrasonic atomizing head. The atomizing tube directed the atomization to the surface of the AgNws film. The diameter of the atomizing tube outlet was 20 mm, and the distance between the outlet and the sample was 20 mm. Nitrogen was used as the carrier gas at a rate of 6 L / min, and the atomization rate was approximately 3 mL / min. The deposition rate of pyrolyzonium acetylacetonate was 10 nm / min, and the deposition thickness was 100 nm.

[0081] S4. Annealing treatment

[0082] The thin film was annealed in a vacuum tube furnace with a vacuum level below 5 Pa, an annealing temperature of 200 °C, and an annealing time of 0.5 h.

[0083] The 100 nm thick pyrolytic zirconium acetylacetonate-protected AgNws transparent conductive film prepared in this embodiment exhibits good transmittance across the entire ultraviolet region, with a transmittance of 81% at 310 nm. The device using this transparent conductive film as a window shows a responsivity of 0.078 AW to 310 nm ultraviolet light. -1 .

[0084] Example 4

[0085] A method for preparing a composite conductive thin film electrode includes the following steps:

[0086] S1. Preparation of AgNws thin films

[0087] A silver nanowire film with a thickness of 35 nm and a sheet resistance of 10 Ω / sq was prepared by depositing a thin film on the substrate surface using silver nanowire ink with a solid content of 12 g / L and a diameter of 25~35 nm, and then annealing it at 100 ℃ for 10 min.

[0088] S2. Preparation of the mixture

[0089] Zirconium acetylacetonate was added to a composite solvent composed of ethanol and dimethylformamide to prepare a mixed solution with a concentration of 0.006 mol / L. The volume ratio of ethanol to dimethylformamide in the composite solvent was 5:1.

[0090] S3. Spray pyrolysis deposition top layer

[0091] The AgNws film was heated to 110 °C. The mixture prepared in step S1 was placed in an atomizing cup and atomized using a 1.4 MHz ultrasonic atomizing head. The atomizing tube directed the atomization to the surface of the AgNws film. The diameter of the atomizing tube outlet was 20 mm, and the distance between the outlet and the sample was 10 mm. Nitrogen was used as the carrier gas at a rate of 10 L / min, and the atomization rate was approximately 15 mL / min. The deposition rate of pyrolyzonium acetylacetonate was 2 nm / min, and the deposition thickness was 20 nm.

[0092] S4. Annealing treatment

[0093] The thin film was annealed in a vacuum tube furnace with a vacuum level below 5 Pa, an annealing temperature of 140 °C, and an annealing time of 10 h.

[0094] The 20 nm thick pyrolytic zirconium acetylacetonate-protected AgNws transparent conductive film prepared in this embodiment exhibits good transmittance across the entire ultraviolet region, with a transmittance of 86% at 310 nm. The device using this transparent conductive film as a window shows a responsivity of 0.085 AW to 310 nm ultraviolet light. -1 .

Claims

1. A transparent composite conductive thin-film electrode for ultraviolet optoelectronic devices, characterized in that: The transparent composite conductive film consists of an electrode bottom layer and a top layer on its surface. The electrode bottom layer is a silver nanowire film, and the top layer is a pyrolytic zirconium acetylacetonate protective layer. The pyrolytic zirconium acetylacetonate protective layer is a precursor solution prepared by using zirconium acetylacetonate as a solute and ethanol and dimethylformamide as a composite solvent. It is deposited on the surface of the silver nanowire film by atomization pyrolysis, and finally vacuum annealing to obtain a protective layer with a composition between zirconium acetylacetonate and zirconium oxide. The pyrolytic deposition temperature of the pyrolytic zirconium acetylacetonate is 110~140 ℃, the deposition rate is 2~10 nm / min, the vacuum annealing is 140~200 ℃, and the annealing time is 0.5~24 h. In the composite solvent, the volume ratio of ethanol to dimethylformamide is 3:1~5:

1.

2. A method for preparing a composite conductive thin film electrode, characterized in that: A precursor solution was prepared using zirconium acetylacetonate as a solute and ethanol and dimethylformamide as a composite solvent. The precursor solution was spray-dried and pyrolyzed onto the surface of a silver nanowire film. Finally, vacuum annealing was performed to obtain a protective layer with a composition between zirconium acetylacetonate and zirconium oxide. The pyrolysis deposition temperature was 110~140 ℃, the deposition rate was 2~10 nm / min, and the deposition thickness was 20~100 nm. The vacuum degree of the vacuum annealing was below 5 Pa, the annealing temperature was 140~200 ℃, and the annealing time was 0.5~24 h. The volume ratio of ethanol to dimethylformamide in the composite solvent was 3:1~5:1, and the concentration of the precursor solution was 0.006~0.05 mol / L.

3. The method for preparing a composite conductive thin film electrode as described in claim 2, characterized in that: The atomizer for the spray pyrolysis uses a 1.4 MHz ultrasonic atomizing head, the diameter of the mist guide tube outlet is 20 mm, the distance between the mist guide tube outlet and the sample is 10~20 mm, the carrier gas is nitrogen, the inlet rate is 6~10 L / min, and the atomization rate is 3~15 mL / min.

4. A method for preparing a composite conductive thin film electrode, characterized in that, Includes the following steps: S1. Preparation of AgNws thin films A silver nanowire film with a thickness of 30-40 nm and a sheet resistance of 10-12 Ω / sq was prepared by depositing a thin film on the substrate surface using silver nanowire ink with a solid content of 8-12 g / L and a diameter of 25-35 nm, and then annealing it at 100 °C for 10 min. S2. Preparation of the mixture Zirconium acetylacetonate was added to a composite solvent composed of ethanol and dimethylformamide to prepare a mixed solution with a concentration of 0.006~0.05mol / L. The volume ratio of ethanol to dimethylformamide in the composite solvent was 3:1~5:

1. S3. Spray pyrolysis deposition top layer The AgNws film was heated to 110-140 °C. The mixture prepared in step S1 was placed in an atomizing cup and atomized using a 1.4 MHz ultrasonic atomizing head. The atomizing head directed the atomizing gas to the surface of the AgNws film through a mist guide tube. The diameter of the mist guide tube outlet was 20 mm, and the distance between the outlet and the sample was 10-20 mm. Nitrogen was used as the carrier gas at a rate of 6-10 L / min, and the atomization rate was 3-15 mL / min. The deposition rate of pyrolyzonium acetylacetonate was 2-10 nm / min, and the deposition thickness was 20-100 nm. S4. Annealing treatment The film was annealed in a vacuum tube furnace at a vacuum level below 5 Pa, an annealing temperature of 140–200 °C, and an annealing time of 0.5–24 h to obtain a protective layer with a composition between zirconium acetylacetonate and zirconium oxide.

Images