Core–Shell Single‐Nanowire Photodetector with Radial Carrier Transport: an Opportunity to Break the Responsivity‐Speed Trade‐off

Abstract

AbstractThe trade‐off between the responsivity and response speed is a key limiting factor for the realization of high‐performance photodetectors. Here, a core–shell single‐nanowire structure with radial carrier transport is proposed for the possibility of breaking this trade‐off. Taking multilayer molybdenum disulfide (MoS2) as the exemplified material, the photoelectric responses of the core–shell nanowire MoS2 photodetector are theoretically predicted and numerically simulated. Thanks to the enhanced light absorptivity and ultra‐short transmission distance of carriers in the nanowire, the photodetector achieves an ultrahigh responsivity with sustaining a short response time. In a wide range of visible spectrum, the responsivity, response time, and specific detectivity of the nanowire photodetector reach 104 A W−1, 230 ps, and 1012 Jones, respectively, according to the optoelectronic simulation. The responsivity‐bandwidth product is predicted up to ≈1013 Hz A W−1, which is at least three orders of magnitude higher than that of the conventional MoS2‐based photodetectors. It is believed that the nanowire design provides a new scheme for promoting the development of the high‐performance photodetectors.