Low-Temperature Large-Area Zinc Oxide Coating Prepared by Atmospheric Microplasma-Assisted Ultrasonic Spray Pyrolysis

Zinc oxide (ZnO) coatings have various unique properties and are often used in applications such as transparent conductive films in photovoltaic systems. This study developed an atmospheric-pressure microplasma-enhanced ultrasonic spray pyrolysis system, which can prepare large-area ZnO coatings at low temperatures under atmospheric-pressure conditions. The addition of an atmospheric-pressure microplasma-assisted process helped improve the preparation of ZnO coatings under atmospheric conditions, compared to using a conventional ultrasonic spray pyrolysis process, effectively reducing the preparation temperature to 350 °C. A program-controlled three-axis platform demonstrated its potential for the large-scale synthesis of ZnO coatings. The X-ray diffraction results showed that the ZnO coatings prepared by ultrasonic spray pyrolysis exhibited (002) preferred growth orientation and had a visible-light penetration rate of more than 80%. After vacuum treatment, the ZnO reached a 1.0 × 10−3 Ωcm resistivity and a transmittance of 82%. The tribology behavior of ZnO showed that the vacuum-annealed coating had a low degree of wear and a low coefficient of friction as the uniformly distributed and dense coating increased its load capacity.