Single-nanowire silicon photodetectors with core-shell radial Schottky junction for self-powering application

Abstract

A silicon (Si) based core-shell single-nanowire photodetector with the radially configured Schottky junction is presented for high-performance self-powering photodetection application. The optoelectronic properties of the device are evaluated by performing a comprehensive device-level simulation using the finite-element method. An extremely high responsivity of 107 A/W at zero bias is predicted, which is three orders higher than that of the axially configured device. Additionally, the time-dependent simulation reveals that the system with the radial semiconductor junction shows a fast response with an unbiased response time of 22 μs. We explore detailedly the underlying mechanisms for the high-performance responses of this nanostructured photodetector. It is found that the single-nanowire design with the radial junction enables a high light absorption in optical domain as well as a very efficient and fast carrier transport in electrical domain.