Enhanced lateral photovoltaic effect in the p-n heterojunction composed of manganite and silicon by side irradiation for position sensitive detecting

Lateral photovoltaic effect has been studied in p-La0.67Ca0.33MnO3/n-Si heterojunction. Under illumination of continuous 808 nm laser beam on the film surface, a transient photovoltaic overshoot accompanied with the steady signal was observed when the laser turned off and on. The open-circuit photovoltage had a linear dependence on illuminated position, and the sensitivity reached 0.75 mVmW(-1)mm(-1) for steady value and 6.25 mVmW(-1)mm(-1) for the transient peak value. Especially, an enhancement in position detecting sensitivity was observed when the interface of this heterojunciton was irradiated, which were 1.25 mVmW(-1)mm(-1) (steady value) and 26.0 mVmW(-1)mm(-1) (peak value). This work demonstrates a novel way to increase sensitivity for manganite-based position sensitive detectors. (C) 2011 Optical Society of America