Solution-Processed Chalcohalides and Chalcohalide/Chalcogenide Heterostructures for Solar Cell Applications

Abstract

Antimony-based materials, such as antimony chalcogenides and chalcohalides, are considered to be an alternative to the hybrid perovksites of next-generation solar cells due to their low-toxicity, defect-tolerant feature, and remakrable photovoltaic performance close to 10%. Recently, we developed a simple solution process for controlled growth of antimony chalcohalides (Fig. 1) and succefully applied it to low-temperature planar SbSI solar cells [1]. This solution process consists of two steps: formation of chalcogenide and conversion to chalcohalide. Very recently, we have found that this method can be applied to the fabrication of heterostructures composed of chalcogenide and chalcohalide. In this talk, I will introduce the preparation of chalcohalides and chalcogenide/chalcohalide heterostructures through the two-step solution process for solar cell application. Various thiol-amine solutions and halide sources were applied in the first and second steps, respectively. This process enabled to fabricate various chalcohalides and heterostructures including SbSI, SbSeI, Sb(S,Se)I, Sb2S3/SbSI, and Sb2Se3/SbSeI. The structures and morphologies of these materials were also controlled for optimial photovoltaic performance. This work is expected to present a new direction for the development of next-generation solar cells.