(001)-oriented Cu2-ySe thin films with tunable thermoelectric performances grown by pulsed laser deposition

Highly (001)-oriented Cu2-ySe thin films with tunable thermoelectric performances have been grown by pulsed laser deposition. By using targets with different Cu/Se ratios that further determines the copper deficiency of as-grown films, the carrier concentrations of as-grown films are tuned within a broad range from 10(18) to 10(21) cm(-3). The optimum performance is observed at carrier concentration similar to 1.58 x 10(20) cm(-3). The distinct properties of Cu2-ySe thin films with nearly ideal chemical stoichiometric ratio are observed. In addition, a weak change in the electrical transport during the second-order phase transition was observed in the thin films due to the anisotropic structure of the Cu2-ySe. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.