Method for controlling performance of humidity-adjusting zinc oxide ultraviolet sensor and humidity-adjusting zinc oxide ultraviolet sensor

Abstract

The invention discloses a method for controlling the performance of a humidity-adjusting zinc oxide ultraviolet sensor and the humidity-adjusting zinc oxide ultraviolet sensor. The method for controlling the humidity to adjust the performance of the zinc oxide ultraviolet sensor comprises the following steps: (1) manufacturing the zinc oxide ultraviolet sensor, (2) testing the zinc oxide ultraviolet sensor under different humidity conditions to obtain a relationship among sensitivity, response time, recovery time and humidity, and (3) controlling or changing the humidity according to the obtained relationship to adjust the performance of the zinc oxide ultraviolet sensor. And adjusting the sensitivity and response recovery time of the zinc oxide ultraviolet sensor. The humidity-controlled zinc oxide ultraviolet sensor comprises a substrate material, a ZnO material, an electrode, a humidity control material, a first packaging material and a second packaging material. The invention further discloses a corresponding manufacturing method. According to the method for adjusting the performance of the zinc oxide ultraviolet sensor by controlling the humidity, the humidity can be controlled, and the performance of the zinc oxide ultraviolet sensor can be adjusted or adjusted according to application requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a method for controlling the performance of a humidity-regulated zinc oxide ultraviolet sensor and the humidity-regulated zinc oxide ultraviolet sensor. Background Art

[0002] Ultraviolet (UV) radiation, an electromagnetic wave with a wavelength between 10 and 400 nm, is ubiquitous in nature and in human life. UV sensors have a wide range of applications in solar physics, space science, semiconductors, environmental monitoring, reconnaissance, and optical information.

[0003] Semiconductor UV sensors have garnered widespread attention and application in recent years due to their small size, light weight, insensitivity to magnetic fields, and low cost. Zinc oxide (ZnO), a Group II-VI wide-bandgap semiconductor material, boasts a bandgap of 3.37 eV and an exciton binding energy of up to 60 meV at room temperature. Its unique crystal structure and excellent physicochemical properties have made it a popular choice for UV photodetection. Furthermore, ZnO offers excellent chemical stability, biocompatibility, and low cost, making it amenable to large-scale production. These advantages have laid a solid foundation for its application in UV sensors.

[0004] Humidity significantly affects the sensitivity and response recovery time of zinc oxide UV sensors. Failure to precisely control the humidity of the environment surrounding the zinc oxide UV sensor can lead to unstable sensor performance. Even if the zinc oxide UV sensor is isolated from the outside environment through packaging, the humidity during packaging can affect its performance, resulting in inconsistent performance between zinc oxide UV sensors produced at different times. However, properly controlling the humidity of the environment surrounding the zinc oxide UV sensor can stabilize sensor performance and adjust its sensitivity and response recovery time as needed.

[0005] The prior art has not reported a method for adjusting the performance of a zinc oxide ultraviolet sensor by controlling humidity, or a technology for obtaining an ultraviolet sensor with stable performance, controllable sensitivity, and controllable response recovery time by controlling humidity. Summary of the Invention

[0006] Aiming at the blank of the prior art in humidity-regulated zinc oxide ultraviolet sensors, the present invention provides a method for controlling the performance of a humidity-regulated zinc oxide ultraviolet sensor and a humidity-regulated zinc oxide ultraviolet sensor.

[0007] In a first aspect of the present invention, a method for controlling humidity to adjust the performance of a zinc oxide ultraviolet sensor is provided, wherein the method is: Step 1: For a certain zinc oxide material, make it into a zinc oxide ultraviolet sensor.

[0008] Step 2: Place the zinc oxide UV sensor in an environment with different humidity, measure the sensitivity, response time, and recovery time of the sensor, and obtain the relationship between the sensitivity, response time, and recovery time and humidity.

[0009] Step 3: Based on the obtained relationship, adjust the performance of the zinc oxide UV sensor using the following methods: Based on the obtained relationship, determine the humidity suitable for the actual application. Use various control methods to stably control the humidity at the desired level, thereby regulating the performance of the zinc oxide UV sensor. Alternatively, the humidity can be switched through various methods to adjust the performance of the zinc oxide UV sensor, allowing the same zinc oxide UV sensor to meet different application requirements.

[0010] In the second aspect of the present invention, a humidity-regulating zinc oxide ultraviolet sensor is provided. It includes a base material, a ZnO material, an electrode, a humidity control material, a first packaging material, and a second packaging material. The base material or the packaging material is made of a material that is transparent to ultraviolet light. The ZnO material is prepared on the surface of the base material, and two electrodes are connected to both sides of the ZnO material. The humidity control material is prepared on the surface of the base material or the first packaging material, and is electrically insulated from the ZnO material and the electrode material. The first packaging material, the second packaging material, and the base material are isolated to form a closed space that accommodates the ZnO material, the electrode, and the humidity control material, so that the ZnO material, the electrode, and the humidity control material are in the same environment and isolated from the external environment. The humidity control material can control the humidity in the closed space to a selected humidity. The first packaging material and the second packaging material can be different materials or the same material.

[0011] A method for preparing a humidity-controlled zinc oxide ultraviolet sensor comprises the following steps: Step 1: Prepare ZnO material in the middle area of the surface of the substrate material.

[0012] Step 2: Make electrodes on both sides of the ZnO material on the base material.

[0013] Step 3: Attach a humidity control material to the area of the base material that is not in contact with the ZnO material and the electrode, or attach a humidity control material to the first packaging material.

[0014] Step 4: Fasten the base material and the first packaging material together, and seal the surrounding gaps with the second packaging material to form an air-enclosed space in the area where the ZnO material, electrodes, and humidity control material are located. This completes the humidity-controlled zinc oxide UV sensor.

[0015] The humidity-controlled zinc oxide ultraviolet sensor of the present invention has the following technical advantages: 1. By controlling the humidity to be stable, the zinc oxide UV sensor has stable performance, solving the problem that the performance of the zinc oxide UV sensor is easily affected by the environmental humidity.

[0016] 2. By controlling the humidity at a lower level, the zinc oxide UV sensor can have a high sensitivity, resulting in a high-precision zinc oxide UV sensor suitable for accurate measurement of low-intensity UV light.

[0017] 3. By controlling the humidity at a higher level, the zinc oxide UV sensor has a low response recovery time, resulting in a fast-response zinc oxide UV sensor that is suitable for measuring rapidly changing UV light. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the corresponding relationship diagram between some salt and humidity when using saturated salt solution to control humidity; Figure 2 Graph showing the relationship between sensitivity, response time, recovery time, and humidity of the zinc oxide UV sensor obtained in Example 1; Figure 3 Schematic diagram of the structure of the zinc oxide ultraviolet sensor of the present invention (the top is the main view, the bottom is the top view); Figure 4 The UV radiation of the zinc oxide sensor obtained in Example 2 was 1 mW / cm 2 Comparison of photocurrent and dark current under ultraviolet light irradiation and corresponding sensitivity; Figure 5 The response and recovery time of the zinc oxide UV sensor were obtained for Example 3; In the figure: 1-base material, 2-ZnO material, 3-electrode, 4-humidity control material, 5-first packaging material, 6-second packaging material. DETAILED DESCRIPTION

[0019] Example 1 Example 1 takes a zinc oxide ultraviolet sensor made of zinc oxide microwire material as an example to explain in detail the method of adjusting the performance of the zinc oxide ultraviolet sensor by controlling humidity: (1) Synthesis of zinc oxide microwires. Weigh 2g of zinc oxide powder and 0.4g of graphite powder and transfer them to an agate mortar. Add a small amount of anhydrous ethanol and grind them to mix thoroughly. Then dry them in an oven. Spread the mixed powder evenly on the bottom of a clean corundum boat and cover the top of the boat with a corundum sheet. Place the corundum boat containing the powder in the center of a high-temperature tube furnace. First, evacuate the tube furnace, then introduce a mixed gas consisting of 190 sccm argon and 5 sccm oxygen, and adjust the pressure in the furnace tube to 7000 Pa. Heat the furnace to 1050°C at a rate of 35°C / min, keep it warm for 45 minutes, and then naturally cool it to 500°C. Stop ventilation and continue to naturally cool it to 200°C. Turn off the vacuum pump, and zinc oxide microwires will be obtained on the edge of the corundum sheet.

[0020] (2) Fabrication of zinc oxide ultraviolet sensors based on zinc oxide microwires. The zinc oxide microwires were transferred to a clean glass sheet, and electrodes were made at both ends using conductive carbon paste. Copper wires were connected to the electrodes using conductive carbon paste to produce zinc oxide ultraviolet sensors based on zinc oxide microwires.

[0021] (3) Sensor performance test under humidity control. The zinc oxide UV sensor based on zinc oxide microwires was placed in a transparent box containing a saturated solution of a specific salt and crystals of the corresponding salt. Figure 1 The corresponding relationship in the equation is used to obtain the corresponding relative humidity. The sensitivity, response time and recovery time of the zinc oxide ultraviolet sensor based on zinc oxide microwires at this humidity are measured. Figure 2 The relationship between the sensitivity, response time and recovery time of the zinc oxide ultraviolet sensor based on zinc oxide microwires and humidity can be obtained. The sensitivity of this zinc oxide ultraviolet sensor increases with decreasing humidity, and the response time and recovery time both decrease with increasing humidity.

[0022] (4) Control humidity to adjust the performance of zinc oxide UV sensor. Figure 2 The results show that, based on actual application needs, appropriate humidity levels can be selected and stably controlled at the selected level through various methods, including saturated salt solutions, drying, and humidification. Placing calcium chloride desiccant in a transparent box provides a dry environment, while adding different saturated salt solutions to the box accurately provides a stable humidity environment within the 3%-98% RH range, enabling the performance of the zinc oxide UV sensor to be controlled. Alternatively, by switching humidity levels through drying and selecting different saturated salt solutions, the performance of the zinc oxide UV sensor can be adjusted, enabling the same zinc oxide UV sensor to meet different application requirements.

[0023] Example 2 The structure of humidity-controlled zinc oxide UV sensor is as follows Figure 3, including substrate material, ZnO material, electrode, humidity control material, and packaging material. The substrate material or packaging material is made of a material that can transmit ultraviolet light. The ZnO material is prepared on the surface of the substrate material, and two electrodes are connected and fixed on both sides of the ZnO material; the zinc oxide micron wire is placed on the substrate material, and the electrode is carbon paste, which can be fixed by applying dots on both sides of the micron wire. The humidity control material is prepared in the groove of the first packaging material, and the groove in the first packaging material electrically insulates the humidity control material from the ZnO material and the electrode material. The second packaging material is applied to the edge of the substrate material so that the substrate material isolates the gap that accommodates the ZnO material, electrode, and humidity control material. Finally, the ZnO material, electrode, and humidity control material are in the same environment and isolated from the external environment.

[0024] Example 2 demonstrates a humidity-controlled zinc oxide UV sensor of the present invention that maintains humidity at 11.4% RH. The sensor uses a glass sheet as the substrate, a plexiglass sheet as the primary encapsulation material, hot melt adhesive as the secondary encapsulation material, and a saturated salt solution hydrogel as the humidity control material. Figure 4 The humidity-regulated ZnO UV sensor was demonstrated in the absence of UV irradiation and with 1 mW / cm 2 The voltammetric curve under ultraviolet light irradiation has a sensitivity of 27371.

[0025] The specific production process is as follows: (1) Synthesis of zinc oxide microwires. Same as Example 1.

[0026] (2) Preparation of zinc oxide ultraviolet sensor. Same as Example 1.

[0027] (3) Preparation of saturated salt solution hydrogel. Weigh excess KCl and add it to deionized water. Heat to 60–70°C and stir until the KCl is completely dissolved. Filter the undissolved solids while hot to obtain a clear saturated solution. Slowly sprinkle 5 g of agarose powder into 100 mL of hot saturated KCl solution. Continue stirring and heat to 85–90°C. Maintain for 15–20 minutes until the solution is transparent and free of particles.

[0028] (4) Fabrication of a humidity-controlled zinc oxide UV sensor. Cut the organic glass plate into small pieces of the same size as the above-mentioned glass sheet, carve a groove on the organic glass plate, and draw a spacer layer on both ends of the organic glass plate with hot melt adhesive. Inject uncooled saturated salt solution hydrogel into the groove. After the hydrogel cools to room temperature, buckle the glass sheet and the organic glass plate together. The presence of the spacer layer leaves a gap between the two, preventing the zinc oxide microwires, electrodes, and wires from contacting the saturated salt solution hydrogel. Use hot melt adhesive to seal the gap around the glass sheet and the organic glass plate to obtain a humidity-controlled zinc oxide UV sensor.

[0029] Example 3 Example 3 demonstrates a humidity-controlled zinc oxide UV sensor of the present invention that maintains humidity at 84.34% RH. The sensor uses a glass sheet as the substrate, a plexiglass sheet as the primary encapsulation material, hot melt adhesive as the secondary encapsulation material, and a saturated salt solution hydrogel as the humidity control material. Figure 5 demonstrated the humidity-regulated ZnO UV sensor using 1 mW / cm 2 The UV light was irradiated for 10 seconds, and then the UV light was turned off for 20 seconds to obtain the relationship between current and time. It can be found that the response time is 3.59 s and the recovery time is 5.286 s.

[0030] The specific production process is as follows: (1) Synthesis of zinc oxide microwires. Same as Example 1.

[0031] (2) Preparation of zinc oxide ultraviolet sensor. Same as Example 1.

[0032] (3) Preparation of saturated salt solution hydrogel. Weigh excess LiCl and add it to deionized water. Heat to 60–70°C and stir until the LiCl is completely dissolved. Filter the undissolved solids while hot to obtain a clear saturated solution. Slowly sprinkle 5 g of agarose powder into 100 mL of hot saturated LiCl solution. Continue stirring and heat to 85–90°C for 15–20 minutes until the solution is transparent and free of particles.

[0033] (4) Fabrication of a humidity-controlled zinc oxide UV sensor. Cut the organic glass plate into small pieces of the same size as the glass sheet above, and carve a groove into the organic glass plate. Inject uncooled saturated salt solution hydrogel into the groove. After the hydrogel cools to room temperature, buckle the glass plate and the organic glass plate together, leaving a gap between them to prevent the zinc oxide microwires, electrodes, and wires from contacting the saturated salt solution hydrogel. Use hot melt adhesive to seal the gaps around the edges to obtain a humidity-controlled zinc oxide UV sensor.

Claims

1. A method for controlling humidity to adjust the performance of a zinc oxide ultraviolet sensor, characterized in that: By controlling or changing the humidity of the environment surrounding the zinc oxide UV sensor, the sensitivity, response time and recovery time of the zinc oxide UV sensor can be adjusted.

2. The method for controlling humidity to adjust the performance of a zinc oxide ultraviolet sensor according to claim 1, wherein: The following steps are involved: (1) Fabrication of zinc oxide UV sensors; (2) Test the zinc oxide UV sensor under different humidity conditions and obtain the relationship curves of sensitivity, response time and recovery time with humidity; (3) According to the relationship curve obtained in step (2), the humidity around the zinc oxide ultraviolet sensor is controlled or changed accordingly to adjust the sensitivity, response time and recovery time of the zinc oxide ultraviolet sensor.

3. A humidity-adjusting zinc oxide ultraviolet sensor according to any one of claims 1 to 2, characterized in that: The zinc oxide ultraviolet sensor comprises a shell, in which ZnO material, electrodes and humidity control material are sealed.

4. The humidity-adjusting zinc oxide ultraviolet sensor according to claim 3, characterized in that: The shell includes a substrate and a first packaging material. The ZnO material and the electrode are located on the substrate. The humidity control material is located on the substrate or the first packaging material. The second packaging material is used to seal the gap between the substrate and the first packaging material.

5. The humidity-adjusting zinc oxide ultraviolet sensor according to claim 4, characterized in that: The substrate or packaging material is made of a material that can transmit ultraviolet light.

6. The humidity-adjusting zinc oxide ultraviolet sensor according to claim 4, characterized in that: The first packaging material, the second packaging material and the substrate are isolated to form a closed space for accommodating the ZnO material, the electrode and the humidity control material.

7. The humidity-adjusting zinc oxide ultraviolet sensor according to claim 3, characterized in that: Humidity control materials are used to control the humidity within an enclosed space to a selected humidity level.

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