Recent Progress on Cu2BaSn(SxSe1–x)4: From Material to Solar Cell Applications

Abstract

Thin film solar cells show great potential applications in building‐integrated photovoltaics (BIPV) and portable devices. Among these thin film solar cells, Cu2BaSn(SxSe1–x)4 solar cells derived from Cu2ZnSn(SxSe1–x)4 solar cells have attracted intense research interests recently because of their high theoretical PCE of ap;31%, easy tunability of band gaps (Eg = 1.28–1.79 eV), large optical absorption coefficient (α > 104 cm−1), environment‐friendly composition, low materials, and fabrication cost. Importantly, Cu2BaSn(SxSe1–x)4 solar cells are expected to have low open‐circuit voltage deficit, leading to high open‐circuit voltage and PCEs. In fact, since their initial development in 2016, the maximum PCE of Cu2BaSn(SxSe1–x)4 solar cells has surpassed 5% via adjustment of the fabrication methods and material properties, optimization of the device structures, and so forth. Here, a review of the recent progress of Cu2BaSn(SxSe1–x)4 solar cells is presented, including properties of Cu2BaSn(SxSe1–x)4, material and device fabrication methods, device performances, potential applications, as well as the bulk and interface recombination. In addition, other solar cells which are similar with the Cu2BaSn(SxSe1–x)4 solar cells are also discussed. Finally, according to these discussions, prospect for PCEs improvement is given to accelerate their development.