Continuous-wave terahertz emitter with hybrid nanoelectrodes based on graphene and nanowire

Continuous-wave terahertz emitters based on photomixers with hybrid nanoelectrodes are investigated. The nanoelectrodes consist of a nitrogen-doped single layer of graphene and silver nanowires, placed on low-temperature-grown (LTG) GaAs as photoconductive material. Due to the high transparency of graphene and the low fill factor of nanowire nanoelectrodes, high photocurrents in the range from 260 µA to 1.8 mA can be reached. Despite their very small size nanoelectrodes provide the capability of handling rather high currents, leading to THz output signals reasonably three times higher than for conventional interdigitated finger electrodes for the whole measurement range. Measurement results of generated photocurrents and THz output signals are presented, showing the increased performance of our approach while maintaining highly reliable operation of the devices.