Effect of transition metals (Sc, Ti, V, Cr and Mn) doping on electronic structure and optical properties of CdS

The influences of transition metals (Sc, Ti, V, Cr and Mn) doping at different distances on the stability, electronic structure, conductivity and optical properties of CdS are studied by using VASP code. The results show that the Cr-doped CdS is easy to form, followed by V, Ti, Sc and Mn. The next nearest-neighbor doping is the most stable in each transition metal-doped system. The band-gaps gradually decrease with the order of Sc, Ti, V, Cr, Mn-doping, all doped systems become the degenerate semiconductor. Doping not only enhances conductivity, but also improves photocatalytic performance, especially Mn-doped CdS has obvious improvement. The absorption intensity in the visible light range of the single-doping is more than that of two atoms doped system in different distances, of which Mn and Cr single-doping are the most prominent.