Effect of Oxygen on the Properties of CdSe Thin Films Prepared by RF-Sputtering

CdSe has been widely used as an absorber for CdTe solar cells due to its ability to lower the optical band gap of CdTe, enhancing device performances. In this study, the effect of oxygen on the microstructural, morphology, composition and hoptoelectrical properties of CdSe films during sputtering and post chloride treatment has been investigated. CdSe:O film transfers to amorphous as oxygen content exceeds 3% in sputtering ambient according to XRD results. The band gap calculated from optical transmission spectra shows the oxygen content in sputtering ambient could tune the band gap of CdSe film from 1.52 eV to 1.97 eV.