Bandgap narrowing in the layered oxysulfide semiconductor Ba3Fe2O5Cu2S2: Role of FeO2 layer

Bandgap narrowing in the layered oxysulfide semiconductor Ba₃Fe₂O₅Cu₂S₂: Role of FeO₂ layer

Zhang Han¹, Jin Shifeng^{1, †,}, Guo Liwei¹, Shen Shijie¹, Lin Zhiping¹, Chen Xiaolong^{1, 2}

(a) Temperature dependence of the resistivity ρ(T) of the Ba₃Fe₂O₅Cu₂S₂ with H = 0. The red line is the fitting results of ρ(T) using thermal activation model. (b) UV-vis-NIR diffuse reflectance spectrum of Ba₃Fe₂O₅Cu₂S₂.