Thin film preparation and characterization of wide band gap Cu3TaQ4 (Q = S or Se) p-type semiconductors

Abstract The structural, optical, and electronic properties of thin films of a family of wide band gap ( E g  > 2.3 eV) p -type semiconductors Cu 3 TaQ 4 (Q = S or Se) are presented. Thin films prepared by pulsed laser deposition of ceramic Cu 3 TaQ 4 targets and ex-situ annealing of the as-deposited films in chalcogenide vapor exhibit mixed polycrystalline/[100]-directed growth on amorphous SiO 2 substrates and strong (100) preferential orientation on single-crystal yttria-stabilized zirconia substrates. Cu 3 TaS 4 ( E g  = 2.70 eV) thin films are transparent over the entire visible spectrum while Cu 3 TaSe 4 ( E g  = 2.35 eV) thin films show some absorption in the blue. Thin film solid solutions of Cu 3 TaSe 4 −  x S x and Cu 3 TaSe 4 −  x Te x can be prepared by annealing Cu 3 TaSe 4 films in a mixed chalcogenide vapor. Powders and thin films of Cu 3 TaS 4 exhibit visible photoluminescence when illuminated by UV light.