Controlled growth of SbSI thin films from amorphous Sb2S3 for low-temperature solution processed chalcohalide solar cells

We report a simple solution processing method for fabricating low-temperature SbSI solar cells. The method consists of two steps: the formation of amorphous Sb2S3 and its transformation to SbSI. A pure SbSI phase with a high crystallinity was obtained at a low temperature of 200 °C. In addition, the SbSI morphology was controlled by tuning the input ratio of SbCl3:thiourea and a dense film was obtained at a ratio of 1:1.3. A planar SbSI solar cell thus-fabricated exhibits a short-circuit current density of 5.45 mA cm−2, an open-circuit voltage of 0.548 V, and a fill factor of 0.31, corresponding to a power conversion efficiency of 0.93% under a 100 mW cm−2 illumination condition.