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

The 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 (MoS 2 ) as the exemplified material, the photoelectric responses of the core–shell nanowire MoS 2 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 10 4 A W −1 , 230 ps, and 10 12 Jones, respectively, according to the optoelectronic simulation. The responsivity‐bandwidth product is predicted up to ≈10 13 Hz A W −1 , which is at least three orders of magnitude higher than that of the conventional MoS 2 ‐based photodetectors. It is believed that the nanowire design provides a new scheme for promoting the development of the high‐performance photodetectors.