Observation of giant persistent photoconductivity on vanadium dioxide thin film device

Abstract

We report a giant persistent photoconductivity (GPPC) phenomenon in VO2 film device prepared on corning glass substrate. With a single pulse laser irradiation onto the device at bias voltages of 7 V and 8 V, the VO2 film makes an insulator-to-metal transition with a sharp increase of photo current. The photo current remained at a highly conductive state for long period, e.g. the photo current for VO2 device was decreased only ~1% in one day. The GPPC was found within the limit of critical voltages of the hysteresis loop in voltage vs current curve of the device. High speed time-current measurements on the device with a 20 ms single pulse laser irradiation revealed that the onset of abrupt photo current occurs in less than 1 ms time scale. The GPPC in VO2 device can contribute in realizing ultrafast optical remote control of advanced electronic devices i.e. optical memories, displays, and remote ultrafast switching devices. © 2020 The Author(s)