CN108807570B

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Publication number: CN108807570B
Application number: CN201810682907.9A
Authority: CN
Inventors: 宿世臣; 孙新雨
Original assignee: South China Normal University
Current assignee: South China Normal University
Priority date: 2018-06-28
Filing date: 2018-06-28
Publication date: 2020-04-14
Anticipated expiration: 2038-06-28
Also published as: CN108807570A

Abstract

The invention discloses a preparation method of a ZnO micron line array ultraviolet detector embedded into a flexible substrate, which comprises the steps of taking zinc powder uniformly placed on a quartz boat and a quartz tube as raw materials, preparing zinc oxide micron lines by a chemical vapor deposition method, transferring the prepared zinc oxide micron lines onto a cleaned glass substrate, arranging the zinc oxide micron lines in order, dripping PVAL glue to cover the surface of the zinc oxide micron lines, removing a zinc oxide micron line array and the PVAL substrate from the glass substrate after the glue is solidified, completing the work of embedding the zinc oxide micron line array into the flexible substrate, and then depositing gold interdigital electrodes on the surface of the zinc oxide micron line array to complete the preparation of the ZnO micron line array ultraviolet detector. The method uses a PVAL flexible substrate, can protect the zinc oxide micron-wire array to the maximum extent, and forms the best contact with the electrode, so that the device is highly integrated.

Description

Preparation method of ZnO micron line array ultraviolet detector embedded in flexible substrate

Technical Field

The invention relates to the field of ultraviolet light detection, in particular to a preparation method of a ZnO micron line array ultraviolet detector embedded in a flexible substrate and used for wearable equipment.

Background

Along with the popularization of intelligent terminals, wearable electronic equipment has a huge market prospect. The flexible wearable detector has the characteristics of portability, thinness, excellent photoelectric performance, high integration level of devices and the like. The ultraviolet detection technology is widely applied to the fields of space communication, ultraviolet interference, ultraviolet guidance, environmental pollution detection, biomedical analysis and the like. The exposure of human eyes or superficial skin tissues to ultraviolet light of a certain intensity can cause various degrees of damage, and is also an important cause of human skin cancer. Therefore, flexible wearable ultraviolet detection equipment for ultraviolet detection has become one of the key points of ultraviolet detection research.

The zinc oxide is a wide-bandgap direct band-gap semiconductor, the bandgap width is 3.37eV at room temperature, the exciton confinement energy is as high as 60meV, the epitaxial growth temperature of the film is lower, the chemical property is stable at room temperature, and the zinc oxide has the advantages of wide source, low price, environmental friendliness and the like. The zinc oxide based ultraviolet detector has high sensitivity, quantum efficiency and responsivity and quick response time.

The zinc oxide based ultraviolet detector is made by preparing zinc oxide nano-wire/micro-wire or film on a substrate. The main preparation methods of the zinc oxide film include metal organic chemical vapor deposition, pulsed laser deposition, molecular beam epitaxy and the like, and the main preparation methods of the zinc oxide nanowire array include chemical vapor deposition and sol-gel method. The zinc oxide film is prepared on a P-type silicon substrate by adopting a pulsed laser deposition method at Zhejiang university. The Suzhou university synthesizes the zinc oxide nanowire by using a chemical vapor deposition method, and the electronic science and technology university deposits a zinc oxide film on a silicon substrate by using a sol-gel method. The sol-gel method has the advantages of low synthesis temperature and simple operation, but the synthesized zinc oxide film has difficultly controlled appearance and lower crystallization quality.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of a ZnO micron line array ultraviolet detector embedded in a flexible substrate, which has the advantages of low cost and simple operation, and zinc oxide micron line arrays are embedded in the flexible substrate, so that compared with the traditional synthesis method of the flexible ultraviolet detector, the zinc oxide micron line arrays can be protected to the greatest extent, and can form the best contact with electrodes, so that the device is highly integrated.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of a ZnO micron line array ultraviolet detector embedded in a flexible substrate comprises the following steps:

s1, cleaning and drying the quartz test tube and the quartz boat for pretreatment;

s2, weighing 5-10 g of zinc powder with the purity of 99.99%, uniformly paving the zinc powder at the bottom of a cleaned quartz boat, placing the quartz boat in a quartz test tube, and placing the quartz test tube in a high-temperature area in the middle of a tube furnace;

s3, heating the tube furnace to a certain temperature within 980-1000 ℃ at a heating rate of 10-15 ℃/min, continuously introducing high-purity nitrogen as a protective gas at a flow rate of 15-20ml/min in the heating process of the tube furnace, stopping introducing the nitrogen when the temperature of the tube furnace reaches the certain temperature, starting introducing high-purity oxygen at a flow rate of 15-20ml/min, and keeping the temperature for 1-1.5 hours;

s4, closing the tube furnace, cooling to room temperature, and taking out the zinc oxide microwire in the quartz test tube for later use;

s5, carrying out cleaning and drying pretreatment on the transparent glass substrate;

s6, placing the pretreated transparent glass substrate on an operation table of a vacuum glove box, transferring zinc oxide microwires onto the transparent glass substrate, arranging the zinc oxide microwires orderly to be fully contacted and attached with the substrate, dropwise adding 1-2ml of PVAL glue to cover the surface of the zinc oxide microwire array, and then placing the zinc oxide microwire array into a drying oven at 60-65 ℃ for keeping for 1-1.5 hours;

s7, stripping the solidified PVAL film from the transparent glass substrate, and depositing gold interdigital electrodes on the surface of the zinc oxide micron line array to complete the preparation of the ZnO micron line array ultraviolet detector.

Further, in step S1, the quartz test tube and the quartz boat are respectively ultrasonically cleaned by distilled water, acetone and ethanol in sequence, and dried for later use.

Further, in step S5, the transparent glass substrate is ultrasonically cleaned with distilled water, acetone and ethanol, then blow-dried with nitrogen gas flow, and then treated in an ultraviolet ozone machine for 30 min.

Furthermore, the gold interdigital electrode uses a stainless steel interdigital electrode as a mask, the interdigital width is 100 μm, the distance is 100 μm, the thickness is 100nm, and 5 pairs of interdigital are provided.

Further, in step S2, 7 g of zinc powder having a purity of 99.99% was weighed.

Further, in step S3, the temperature of the tube furnace is raised to 990 ℃ at a heating rate of 10-15 ℃/min, high-purity nitrogen is continuously introduced as a protective gas at a flow rate of 15ml/min during the heating process of the tube furnace, when the temperature of the tube furnace is raised to the temperature, the introduction of the nitrogen is stopped, high-purity oxygen is introduced at a flow rate of 15ml/min, and the temperature is maintained for 1 h.

Further, in step S6, after 2ml of pval glue is dropped dropwise to cover the surface of the zinc oxide nanowire array, the nanowire array is placed in a drying oven at 60 ℃ and kept for 1 hour.

Further, the transparent glass substrate can be replaced with a sapphire substrate or a quartz substrate.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the preparation method of the ZnO micron line array ultraviolet detector embedded in the flexible substrate has low cost and simple operation, and the zinc oxide micron line array is embedded in the flexible substrate.

Drawings

Fig. 1 is a schematic diagram of a zinc oxide microwire array ultraviolet detector embedded in a flexible substrate inembodiment 1 of the present invention.

FIG. 2 is a scanning electron microscope image of the zinc oxide microwires constituting the ultraviolet detector selected in example 1 of the present invention.

Fig. 3 is a graph of the photoresponse of the zinc oxide microwire array ultraviolet detector embedded in the flexible substrate under different bending angles in example 1 of the present invention.

Fig. 4 is a response time spectrum of the zinc oxide microwire array ultraviolet detector embedded in the flexible substrate under different bending angles in theembodiment 1 of the present invention.

Wherein, the substrate is 1-PVAL, the 2-zinc oxide micron line and the 3-gold electrode.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Example 1:

the embodiment provides a preparation method of a ZnO micron line array ultraviolet detector embedded in a flexible substrate, which comprises the following steps:

s1, cleaning and drying the quartz test tube and the quartz boat for pretreatment, respectively ultrasonically cleaning the quartz test tube and the quartz boat by sequentially adopting distilled water, acetone and ethanol, and drying for later use;

s2, weighing 5 g of zinc powder with the purity of 99.99%, uniformly paving the zinc powder at the bottom of a cleaned quartz boat, placing the quartz boat in a quartz test tube, and placing the quartz test tube in a high-temperature area in the middle of a tube furnace;

s3, heating the tube furnace to 980 ℃ at a heating rate of 10 ℃/min, continuously introducing high-purity nitrogen as a protective gas at a flow rate of 15ml/min in the heating process of the tube furnace, stopping introducing the nitrogen when the temperature of the tube furnace reaches the temperature, starting introducing high-purity oxygen at a flow rate of 15ml/min, and keeping the temperature for 1 h;

s5, cleaning and drying the transparent glass substrate, carrying out ultrasonic cleaning on the transparent glass substrate by adopting distilled water, acetone and ethanol in sequence, blow-drying by using nitrogen airflow, and placing the glass substrate in an ultraviolet ozone machine for treatment for 30 min;

s6, placing the pretreated transparent glass substrate on an operation table of a vacuum glove box, transferring zinc oxide microwires onto the transparent glass substrate, arranging the zinc oxide microwires orderly to be fully contacted and attached with the substrate, dropwise adding 2ml of PVAL glue to cover the surface of the zinc oxide microwire array, and then placing the zinc oxide microwire array into a drying oven at 60 ℃ for keeping for 1 hour;

s7, stripping the solidified PVAL film from the transparent glass substrate, and depositing gold interdigital electrodes on the surface of the zinc oxide micron-line array, wherein the gold interdigital electrodes use stainless steel interdigital electrodes as a mask plate, the interdigital finger width is 100 microns, the distance is 100 microns, the thickness is 100nm, and 5 pairs of interdigital electrodes are used to complete the preparation of the ZnO micron-line array ultraviolet detector.

The scanning electron microscope image of the selected zinc oxide microwire is shown in fig. 2, and the prepared ZnO microwire array ultraviolet detector embedded in the flexible substrate is shown in fig. 1, wherein 1 is a PVAL substrate, 2 is the zinc oxide microwire, and 3 is a gold electrode. The prepared ultraviolet detector is characterized, and the photoresponse spectra of the zinc oxide microwire array ultraviolet detector embedded in the flexible substrate under different bending angles are shown in fig. 3, and the comparison shows that the photoresponse is maximum when the bending angle is 0 degrees, and the photoresponse is gradually reduced along with the increase of the bending angle, but under the condition of the maximum bending angle of 180 degrees, the device still has response and does not fail, which indicates that the device can still work under extreme conditions. The response time maps of the zinc oxide microwire array ultraviolet detector embedded in the flexible substrate at different bending angles are shown in fig. 4, and it can be seen from the graphs that the rise time of the device is 4.8 mus, and the fall time of the device decreases with the increase of the bending angle, which shows that the response speed of the device is slightly improved under the larger bending condition.

Example 2:

the embodiment provides a preparation method of a ZnO micron linear array ultraviolet detector embedded in a flexible substrate, the experimental conditions are the same as those ofembodiment 1, except that in step S2, 7 g of zinc powder with the purity of 99.99% is weighed, in step S3, a tubular furnace is heated to 1000 ℃ at the heating rate of 15 ℃/min, high-purity nitrogen is continuously introduced at the flow rate of 20ml/min in the heating process of the tubular furnace to serve as a protective gas, when the temperature of the tubular furnace is raised to the temperature, the introduction of the nitrogen is stopped, the introduction of the high-purity oxygen is started at the flow rate of 20ml/min, and the temperature is kept for 1.5 hours; in step S6, 1ml of PVAL glue is dripped dropwise to cover the surface of the zinc oxide nanowire array, and then the zinc oxide nanowire array is placed into a drying oven at 65 ℃ for 1.5 hours.

Example 3:

the embodiment provides a preparation method of a ZnO micron linear array ultraviolet detector embedded in a flexible substrate, the experimental conditions are the same as those ofembodiment 1, except that in step S2, 10 g of zinc powder with the purity of 99.99% is weighed, in step S3, a tube furnace is heated to 990 ℃ at the heating rate of 13 ℃/min, high-purity nitrogen is continuously introduced at the flow rate of 17ml/min in the heating process of the tube furnace to serve as a protective gas, when the temperature of the tube furnace is raised to the temperature, the introduction of the nitrogen is stopped, the introduction of the high-purity oxygen is started at the flow rate of 17ml/min, and the temperature is kept for 1.3 h; in step S6, 1.5ml of pval glue is dropped dropwise to cover the surface of the zinc oxide nanowire array, and then the zinc oxide nanowire array is placed in a drying oven at 63 ℃ for 1.3 hours.

Example 4:

the present embodiment provides a method for manufacturing a ZnO microwire array uv detector embedded in a flexible substrate, and the experimental conditions are the same as those inembodiment 1, except that the transparent glass substrate can be replaced with a sapphire substrate or a quartz substrate.

Example 5:

the embodiment provides a preparation method of a ZnO micron linear array ultraviolet detector embedded in a flexible substrate, the experimental conditions are the same as those ofembodiment 1, except that in step S2, 10 g of zinc powder with the purity of 99.99% is weighed, in step S3, a tube furnace is heated to 990 ℃ at the heating rate of 10 ℃/min, high-purity nitrogen is continuously introduced at the flow rate of 15ml/min in the heating process of the tube furnace to serve as a protective gas, when the temperature of the tube furnace is raised to the temperature, the introduction of the nitrogen is stopped, the introduction of the high-purity oxygen is started at the flow rate of 15ml/min, and the temperature is kept for 1 h; in step S6, after 2ml of pval glue was dropped drop by drop to cover the surface of the zinc oxide nanowire array, the nanowire array was placed in a drying oven at 60 ℃ and kept for 1.5 hours.

The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution of the present invention and the inventive concept within the scope of the present invention, which is disclosed by the present invention, and the equivalent or change thereof belongs to the protection scope of the present invention.

Claims

1. A preparation method of a ZnO micron line array ultraviolet detector embedded in a flexible substrate is characterized by comprising the following steps:

s3, heating the tube furnace to 990 ℃ at a heating rate of 10-15 ℃/min, continuously introducing high-purity nitrogen as a protective gas at a flow rate of 15-20ml/min in the heating process of the tube furnace, stopping introducing the nitrogen when the temperature of the tube furnace reaches the temperature, starting introducing high-purity oxygen at a flow rate of 15-20ml/min, and keeping the temperature for 1-1.5 hours;

s7, stripping the solidified PVAL film from the transparent glass substrate, and depositing gold interdigital electrodes on the surface of the zinc oxide micron-line array, wherein the interdigital fingers have the width of 100 microns, the spacing of 100 microns and the thickness of 100 microns, so that the preparation of the ZnO micron-line array ultraviolet detector is completed.

2. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: and step S1, respectively carrying out ultrasonic cleaning on the quartz test tube and the quartz boat by using distilled water, acetone and ethanol in sequence, and drying for later use.

3. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: and step S5, ultrasonically cleaning the transparent glass substrate by using distilled water, acetone and ethanol in sequence, blow-drying by using nitrogen airflow, and treating in an ultraviolet ozone machine for 30min after blow-drying.

4. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: the gold interdigital electrode uses a stainless steel interdigital electrode as a mask plate, and the number of the gold interdigital electrode is 5.

5. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: in step S2, 7 g of zinc powder having a purity of 99.99% was weighed.

6. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: in step S3, the temperature of the tube furnace is raised to 990 ℃ at a heating rate of 10-15 ℃/min, high-purity nitrogen is continuously introduced at a flow rate of 15ml/min as a protective gas in the heating process of the tube furnace, when the temperature of the tube furnace is raised to the temperature, the introduction of the nitrogen is stopped, high-purity oxygen is introduced at a flow rate of 15ml/min, and the temperature is kept for 1 h.

7. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: in step S6, after 2ml of pval glue was dropped drop by drop to cover the surface of the zinc oxide nanowire array, the nanowire array was placed in a drying oven at 60 ℃ and kept for 1 hour.

8. The method for preparing the ZnO micron line array ultraviolet detector embedded in the flexible substrate according to claim 1, wherein the ZnO micron line array ultraviolet detector is characterized in that: the transparent glass substrate can be replaced with a sapphire substrate or a quartz substrate.

9. A ZnO micron line array ultraviolet detector embedded in a flexible substrate, which is characterized in that the ultraviolet detector is prepared by the preparation method of the claims 1-8.