One-Dimensional Chains in Pentanary Chalcogenides A<sub>2</sub>Ba<sub>3</sub>Cu<sub>2</sub>Sb<sub>2</sub>S<sub>10</sub> (A = K, Rb, Cs) Displaying a Photocurrent Response
Chang Liu, Yu Xiao, Huan Wang, Wen‐Xiang Chai, Xiaofeng Liu, Dongming Yan, Hua Lin, Yi Liu
Abstract
The discovery of new inorganic functional chalcogenides is of fundamental importance in structure chemistry and materials science. Herein, a new type of pentanary thioantimonates, A2Ba3Cu2Sb2S10 (A = K, Rb, Cs), has been discovered by a solvothermal method at low temperature. These isostructural compounds belong to the monoclinic space group C2/m (No. 12) and comprise unique one-dimensional (1D) [Cu2Sb2S10]8– chains surrounded by discrete A+ and Ba2+ cations. Such a 1D chain structure is the first case of chalcogenides in the X/Cu/Sb/Q (X = cations; Q = chalcogen) system. The energy gaps range from 1.90 to 1.98 eV for A2Ba3Cu2Sb2S10 (A = K, Rb, Cs) were obtained from the UV–visible reflectance spectroscopy. Moreover, Rb2Ba3Cu2Sb2S10 displays an intriguing photocurrent response under simulated solar-light illumination. The theoretical calculations were also carried out to understand the interrelationship of the optical performance and electronic structure.