Structure, optical, and electrical properties of layered oxychalcogenide Sr2ZnCu2(S1−x Se x )2O2 (0 ≤ x ≤ 1) compounds

Abstract

Layered oxychalcogenide Sr2ZnCu2(S1-x Se x )2O2 compounds were synthesized via a solid-state reaction. Density functional theory calculations indicate different valence band maximum, Sr2ZnCu2Se2O2 was composed of Cu 3d–Se 4p, while Sr2ZnCu2S2O2 was dominated by the Zn 3d–O 2p hybrid orbital. Band gap was decreased as the Se-containing is increasing, from 2.5 eV to 2.2 eV. In contrast, electrical conductivity of the Se-substituted samples considerably increased from 10−3 S cm−1 at x = 0 to 10−1 S cm−1 at x = 0.25, and was almost the same at x = 1. Based on this feature, Sr2ZnCu2(S1-x Se x )2O2 can be applied as a transparent conductor material.