Impact of channel scaling on performance of single SiC nanowire UV photodetector

Abstract

We have investigated the channel length dependence of the key performance parameters, such as speed, responsivity, external quantum efficiency (EQE), and responsivity-bandwidth product, of the silicon carbide nanowire-based ultraviolet (UV) photodetector devices with different channel lengths ranging from 120 to 800 nm. The device with the shortest channel length of 120 nm at low bias voltage of 0.5 V exhibited very high responsivity and EQE of 7.73 × 10 3 A∕W and 7.77 × 10 4 %, respectively, under illumination to 254-nm UV light. Our experiments revealed that reduction in channel length resulted in significant enhancement in speed, responsivity, EQE, and responsivity-bandwidth product of the photodetector. This study suggests that scaling down in channel length could enable the development of high-speed and sensitive photodetector devices for emerging nanophotonic and nanoelectronic applications capable of operating at low voltages.