Ultrahigh position sensitivity and fast optical relaxation time of lateral photovoltaic effect in SbSe/p-Si junctions.

A large lateral photovoltaic (LPV) effect with good linearity and fast response time is necessary for developing high-performance position-sensitive detectors (PSD). In this paper, we investigated the influence of the resistance of SbSe film and the Si on the LPV properties of the SbSe/p-Si junctions. The LPV exhibits a linear dependence on the laser spot position, with a maximum position sensitivity as high as 448 mV/mm. The optical relaxation time of the LPV was about 4.98 μs, which was due to the formation of the inversion layer at the SbSe/p-Si interface. Our results revealed that the high resistivity of SbSe film facilitate the LPV and confirmed the resistivity of Si substrate play a key role in the LPV properties. The giant position sensitivity and fast relaxation times of the LPV suggest that the SbSe/p-Si junction is a promising candidate for a wide range of optoelectronic device applications.