Origin of photovoltaic effect in (Bi, Pb)2Sr2Ca2Cu3O10+δ /Ag heterostructure

We report I-V characteristics and remarkable photovoltaic effect of (Bi, Pb)2Sr2Ca2Cu3O10+δ/Ag (Bi-2223/Ag) heterostructure in the temperature range between 50 K and 340 K induced by purple-laser irradiation, which is closely related to the superconductivity of Bi-2223 and the charge transfer between silver electrode and the superconductor. Obvious photo-induced voltage has been observed in the whole temperature range with two polarity reversals...