“…Such quaternary chalcogenides with I = {Cu, Ag}, II = {Zn, Cd}, III = {Ga, In}, IV = {Ge, Sn}, and VI = {S, Se, Te} have been synthesized by different groups [2,3,7]. In particular, Cu-based chalcogenides Cu 2 -II-IV-VI 4 can be found at the center of various technological innovations.…”