Towards the development of a self-powered vacuum ultraviolet photodetector based on calcium fluoride/gold interface

•A CaF2/Au interface was investigated as a vacuum ultraviolet photovoltaic sensor.•The sensor is only responsive to vacuum ultraviolet wavelengths without any filters.•Rectification is confirmed in the time response and the I-V characteristic curves.•The sensor’s time response is almost the same as a commercial diamond UV sensor.•The sensor’s characteristics, attributed to surface defects, are investigated.