Method for preparing ZnO thick film

Abstract

The invention provides a method for preparing a ZnO thick film. The method comprises the following steps: dispersing flaky basic zinc salt grains into water to form precursor slurry; filtering the precursor slurry by a microporous filtering film to make the flaky basic zinc salt grains autogenously assembled into an orientation basic zinc salt thick film; transferring the basic zinc salt thick film on the microporous filtering film onto a substrate; and heating and decomposing the thick film to obtain the ZnO thick film. The method uses the flaky basic zinc salt as the precursor to prepare the ZnO thick film, and the prepared ZnO thick film has the advantages of good orientation, even thickness and stable structure.

Description

technical field [0001] The invention relates to a method for preparing zinc oxide thick film. Background technique [0002] ZnO thick film is an important gas-sensing material, which has the advantages of good stability and high selectivity, so it has an important application prospect in gas detection. Traditional ZnO thick films are generally prepared by coating and sintering process, and the process is generally as follows: (1) Synthesize ZnO precursor powder; (2) Grind ZnO powder with dopant and solvent into slurry; (3) Grind the material The slurry is coated on the substrate; (4) the substrate coated with the slurry is sintered. The disadvantages of this process are: (1) ZnO polycrystalline powder and its doping are realized by mechanical mixing, the doping is uneven, the crystal grains are too agglomerated or loose, and the microstructures such as grain boundaries, pores, and crystal orientations are difficult to control, etc., resulting in Thick film is easy to peel ...

AI Technical Summary

Problems solved by technology

The disadvantages of this process are: (1) ZnO polycrystalline powder and its doping are realized by mechanical mixing, the doping is uneven, the crystal grains are too agglomerated or loose, and the microstructures such as grain boundaries, pores, and crystal orientations are difficult to control, etc., resulting in Thick film is easy to peel off, low sensitivity and stability decline; (2) Because the coating process is difficult to ensure the thickness uniformity of thick film, resulting in large differences in film resistance and gas sensing performance between components, which is not conducive to the standardization of gas sensor components; (3) Due to the uncertainty of the coating process, it is difficult to control the microstructure and gas-sensing properties of ZnO thick film stably, which makes it difficult to explore the gas-sensing mechanism of ZnO materials.

[0004] At present, there are coating methods, Langmuir-Blodgett (LB) method, layer-by-layer assembly method, solvent evaporation method and in-situ growth method for the preparation of hydrotalcite-like material films, but most of the above methods are for nano-sheet particles. and the prepared film is usually selective to the substrate, it is difficult to prepare a dense thick film

However, for the large-grain flake basic zinc salt, the above-mentioned process cannot be used to prepare a dense thick film. Therefore, it is necessary to seek a new film-forming process to prepare a thick film of basic zinc salt, and then pyrolyze it to obtain a high-quality zinc oxide thick film. very necessary

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