Hot-Electron Photodetection Based on Graphene Transparent Conductive Electrode

Excited in metal nanoantennas by surface plasmons, the hot electrons with high energy can pass through the Schottky barrier between metal and semiconductor to form photocurrent. Because the energy required to excite hot-electrons is lower than the bandgap of the semiconductor of silicon, the photodetectors can obtain a wider detection spectrum, including the communication wavelengths. In recent years, the two-dimensional material of graphene has attracted wide attention due to its excellent optical transmissivity and electrical conductivity. In this paper, hot-electron photodetectors based on graphene transparent conductive electrode are proposed. Compared with the device utilizing Indium Tin Oxide (ITO) as transparent conductive electrode, the responsivity of the proposed device is greatly enhanced, which achieves 27.5 nA/mW and 17.4 nA/mW for wavelength of 1520 nm and 1550 nm respectively. This study shows that the proposed hot-electron photodetector with graphene transparent conductive electrode possesses great potential in optical communication.