Observation of giant persistent photoconductivity on vanadium dioxide thin film device

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 similar to 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. (C) 2020 The Author(s). Published by Elsevier Ltd.