The Effect of Ar Gas Flow Rate on Structure and Optical Properties of Magnetron Sputtered Sb2Se3 Thin Films for Solar Cells

Recently, antimony selenide (Sb2Se3) absorber layer attracts so much attention in photovoltaic industry since it contains earth abundant, low cost and non-toxic elements contrary to other chalcogenide based solar cells. In the present work, Sb2Se3 absorber films were grown by radio-frequency (RF) magnetron sputtering technique using binary single target and employing various argon flow rates, and then they were annealed under argon atmosphere inside a tubular furnace. Sb2Se3 thin films were investigated using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, and UV-VIS NIR spectrophotometer. The effects of argon flow rate, one of the sputtering parameters, on the properties of the Sb2Se3 films were investigated. The significance of argon flow rate, that used during film deposition, on the observing of Se loss, antimony oxide formation and the change in the surface morphology was also addressed. We observed that the dominant crystal orientation varied with respect to argon flow rate. It was further detected that high argon flow rates cause the decomposition of Sb2Se3 structure and formation of antimony oxide phase. The overall analyses revealed that argon flow rate used while sputtering is effective in changing the structural, and optical properties of the Sb2Se3 thin films.