Integrated atmospheric microplasma with ultrasonic spray pyrolysis deposition of aluminum-doped zinc oxide

Aluminum-doped zinc oxide (AZO) has electrical conductivity and visible light transmittance similar to those of indium tin oxide that is used in modern display devices at a lower price. Thus, many studies regarded it as an alternative material for transparent conductive oxide coating. This study has integrated atmospheric microplasma with an ultrasonic spray pyrolysis deposition system to prepare economically and rapidly AZO using zinc chloride and aluminum chloride as precursors. The low electrical resistivity of the coating prepared in this system is proposed to be due to free radicals and reactive oxygen. They are generated by the atmospheric plasma that is adsorbed to the layer, thereby decreasing oxygen vacancy and free carrier concentration. Vacuum annealing heat treatment was used to improve the properties of the coating; the resistivity of argon-annealed AZO was 5.2 +/- 1.1 x 10-3 omega-cm with 80% transmittance, thus meeting the transparent conducting oxide requirements.