Electric-Induced Nonvolatile Enhancement of Lateral Photovoltaic Effect Observed in Chromium Nanofilm

Lateral photovoltaic effect (LPE) is utilized in position-sensitive detectors (PSDs), which have a wide application in a variety of sensors. Obtaining a higher position-sensitivity is a central issue in the photodetection field. In this letter, a type of electric-induced nonvolatile enhancement of LPE is observed in the metal-oxide-semiconductor nanofilm of Cr/SiO
₂
/Si. This LPE exhibits asymmetric behavior near the electrode, where an electric pulse is applied to locally modulate the transport of photoelectrons. By varying the pulse polarity, the sensitivity can be easily switched between the high LPV state and the low LPV state. The obtained sensitivity is nonvolatile and increases from 31.5 to 68.9 mV/mm through a simple positive pulse switch process. This method is convenient, because it does not require modulating the structure or applying a persistent external field. The shift of Fermi level and the diffusion of photoelectrons contribute a lot to this effect. These findings offer an effective way to enhance the sensitivity and will be useful in the development of LPE-based photodetection devices.