Effect of deposition pressure on the properties of magnetron sputtering-deposited Sb2Se3 thin-film solar cells

Abstract

Antimony selenide (Sb2Se3) thin films were deposited by RF magnetron sputtering using a stoichiometric binary target onto the FTO glass substrates with various working pressures ranging from 0.3 to 10 Pa at room temperature and annealed at 300 °C in inert atmosphere. It was observed that the morphologies and microstructure were strongly affected by the working pressure. The Sb2Se3 thin films had [hk0] orientation preference at 0.3 Pa and 2 Pa, while the films were found to be easier to grow inclined to [hk1] direction at 5 Pa, 8 Pa, and 10 Pa in this work. As expected, the samples deposited at higher pressures exhibited better conductivity and the highest photocurrent reached about 580 μA when illuminated by a white LED with a power density of 5 mW cm−2. The Se losses were observed both during the sputtering and annealing processes. The solar cells were fabricated with a superstrate structure and the defects in the sputtered Sb2Se3 absorbers were analyzed.