Using an appropriate SeS₂/Se weight ratio, band gap grading was realized. By increasing the value ofV_OCthrough band gap grading in the depletion region, a recordV_OCdeficit of 0.576 V and an efficiency of 12.3% were obtained.

We fabricated CZTSSe thin films using optimized SLG-Mo/Zn/Cu/Sn (MZCT) as a stacked structure and described the phenomenon of Zn elemental volatilization using the MZCT stacked structure. We introduced H₂S gas to effectively control the S/(S + Se) ratio of the film in the sulfo-selenization process and to suppress Zn volatilization. Unlike during the selenization process, a stable ZnSSe thin film was formed on the precursor surface during the sulfo-selenization process. The formation of the ZnSSe thin film inhibited Zn volatilization, which facilitated control of the thin film stoichiometry and played an important role in crystal growth. In addition, the sulfo-selenization process using H₂S forms a grading of the S/(S + Se) ratio in the depth direction in the ZnSSe layer. The ZnSSe layer with this property causes the band gap grading in the CZTSSe absorption layer. Finally, through our optimized annealing process, we realized a world record CZTSSe solar cell with a certified power conversion efficiency of 12.62% and a centimetre-scale (1.1761 cm²) efficiency of 11.28%.

A high-quality Sb ₂ S ₃ thin-absorber with controllable thickness was reproducibly formed by atomic layer deposition (ALD) technique.

In this paper, we propose that the microstructural control of (hk1) preferentially oriented Sb₂Se₃films from flat films to rod arrays can improve their photovoltaic efficiency by maximizing the carrier transport characteristics.

Stainless steel (SS) foil is made of abundant materials and is a durable and flexible substrate, but the efficiency of a solar cell on SS foil deterioratesviathe diffusion of impurities from the SS substrate into a Cu₂ZnSn(S,Se)₄(CZTSSe) absorber layer.