Preparation and optical properties of W-doped VO2/AZO bilayer composite film

Abstract

In order to improve its visible light transmittance, W-doped VO2 thin film was prepared with direct current (DC) reactive magnetron sputtering on the surface of Al-doped ZnO (AZO) thin film deposited on quartz glass substrate in advance with radio frequency (RF) magnetron sputtering. The effects of sputtering power for AZO film were investigated on the crystal structures, surface morphologies and optical properties of AZO thin film and W-doped VO2/AZO bilayer composite film. The results show that the crystallinity of both AZO monolayer film and the bilayer film first increases and then decreases with the increase of sputtering power. As the sputtering power increases, the film thickness increases. The integral visible luminous transmittance (Tlum) of the W-doped VO2/AZO bilayer film decreases continuously, and the solar modulation efficiency (ΔTsol) increases first and then decreases. When the sputtering power is 150 W, Tlum and ΔTsol of W-doped VO2/AZO bilayer film are 30.14% and 11.95%, 2.77% and 1.71% higher than those of W-doped VO2 monolayer film, respectively.