Ultraviolet photovoltage characteristics in ZnO/La0.7Sr0.3MnO3 heterostructure

Ultraviolet photovoltage characteristics have been observed in a ZnO/La0.7Sr0.3MnO3 heterostructure, which exhibits reproducible rectifying characteristics. The peak photovoltage is about 0.704 V and the rise time is about 10 ns for the photovoltaic pulse at T = 78K when the heterostructure is irradiated by a 248 nm laser pulse of 25 ns duration. The peak photovoltages and the full widths at half-maximum decrease with increasing temperature. These might be attributed to the change in the fractions of the ferromagnetic insulating phases in the depletion layer.