Enhanced Photovoltaic Properties in Sb2S3 Planar Heterojunction Solar Cell with a Fast Selenylation Approach

Poor thermostability of Sb2S3 in vacuum hinders the possibility of achieving high-quality crystalline films. In order to enhance the photovoltaic properties of Sb2S3 planar heterojunction solar cells, a selenylation-based post-treatment approach has been employed. Selenylation performed over 15 min on the Sb2S3 film resulted in an enhancement in the conversion efficiency from ~ 0.01 to 2.20%. Effect of the selenylation on the evolution of morphology, crystal structure, composition distributions, and photovoltaic behavior has been investigated. The variation in the energy levels of Sb2S3/CdS junction has been also been discussed. Results show that selenylation not only enhanced the crystallinity of Sb2S3 film but also provided a suitable energy level which facilitated charge transport from absorber to the buffer layer.