(Cu2S2)(Sr3SC2O5)-A Layered, Direct Band Gap, p-Type Transparent Conducting Oxychalcogenide: A Theoretical Analysis.

Development or a p-type TCO to rival the high-performance n-type TCOs presently utilized in many applications is one of the grand challenges for materials scientists. However, most of the p-type TCOs fabricated to date have suffered from limited hole mobilities, low conductivities, and indirect band gaps. Recently, [Cu2S2][Sr3SC2O5] has been identified as a possible p-type TCO material, with improved hole mobility. In this article, we study the geometry and electronic structure Of [Cu2S2][Sr3SC2O5] using both GGA + U and HSE06, We show conclusively that [Cu2S2][Sr3SC2O5] is a direct band gap material, with a hole effective mass at the valence band maximum that indicates the potential for good p-type conductivity, consistent with the reported experimental results. These results are discussed in relation to other p-type TCO materials.