The valence band of metal sulfides is usually composed of 3p orbitals of S, which has a more negative valence band and a narrower band gap than metal oxides [33]. Most of the current research focuses on Cd S, Zn S and their solid solutions.
The valence band of metal sulfides is usually composed of 3p orbitals of S, which has a more negative valence band and a narrower band gap than metal oxides [33]. Most of the current research focuses on Cd S, Zn S and their solid solutions.