Fabrication of Sb2S3 solar cells by close space sublimation and enhancing the efficiency via co-selenization

As a new-type absorber material, antimony sulfide (Sb2S3) possesses the advantages of earth-abundant elemental contents, low-toxic constituents, appropriate photoelectric properties, and unique one-dimensional crystal structure. We utilized the close space sublimation technique to deposit high-quality Sb2S3 thin-film with (hk1)-preferred orientation by controlling source temperature. Then, Sb2S3 thin film solar cells with the superstrate structure of FTO/CdS/Sb2S3/Au were fabricated, achieving a conversion efficiency of 2.86%. To further enhance efficiency, co-selenization process was employed in the Sb2S3 thin films by co-sublimation, which improve the crystallinity of films, increase grain size and form stronger (hk1)-preferred orientation. In addition, co-selenization process can adjust band gap value and enhance junction quality. By these approaches, we enhanced the short circuit current density (Jsc) of Sb2S3 solar cell efficiently. The Sb2S3 solar cell fabricated by CSS achieved an efficiency of 4.45% using co-selenization process. These methods can be applied to other chalcogenides thin-film solar cells, providing a practical way for the device performance improvement.