The investigation of transition metal doped CuGaS2 for promising intermediate band materials

Here, we have systematically investigated the electronic structure and optical properties of transition metal (M) doped CuGaS2 (M = Fe, Co, and Ni) systems, using a density functional theory by considering a non-local interaction. Isolated intermediate bands (IBs), with the potential of achieving the efficiency of photovoltaic materials, are introduced in the main band gap of the host CuGaS2 by doping Fe or Ni with a favorable position and width. Therefore, extra absorption peaks appear in the optical spectrum of the Fe and Ni doped CuGaS2 compounds, accompanied with a greatly enhanced light absorption intensity and a largely broadened light absorption energy range. Whereas for Co doped CuGaS2, the material turns into a half-metal. Consequently, Fe and Ni doped CuGaS2 could be potential materials for future applications in the photovoltaic area.