Photovoltaic effect of YBa 2 Cu 3 O 7−δ /SrTiO 3 :Nb heterojunction annealed in different oxygen partial pressure

A large open-circuit voltage (Voc) of 1.04V and a photo-induced short-circuit current density (Jsc) of 84.3μA/cm2 were obtained for YBa2Cu3O7−δ/SrNb0.1Ti0.9O3 (YBCO/NSTO) heterojunction under simulated solar irradiation. The photovoltaic effects of this heterojunction are found to be strongly dependent of annealing oxygen partial pressure. The results are discussed in terms of structural transition from a p–n junction to a Schottky junction as the annealing oxygen pressure changes. Our results indicate that the oxygen concentration of YBCO can be optimized to improve the photovoltaic behaviour of the heterojunction and lead to possible applications in photoelectronic devices and solar cells.