Fig. 7

Heterojunction photovoltaic VUV photodetectors with graphene [107]. a Transmittance of graphene on electromagnetic waves from VUV to near-infrared band. b Schematic diagram of the structure and response mechanism of a heterojunction photovoltaic detector. c Voltage output characteristics of the photovoltaic detector under different lighting conditions. The device outputs an open circuit voltage of 1.7 V under 185 nm light. But under 250 nm light, the device does not have any open-circuit voltage output, remaining the same under dark state. d Relationship between time (ms) and normalized ΔV. The rise time and decay time are 80 ns and 0.4 ms, respectively