1D Core–Shell Radial Heterojunction for High-Performance and Self-Powered Broadband Photodetector

Abstract

Through strategic engineering of component composition and energy band alignment, 1D core–shell nanostructures can be precisely designed as suitable radial heterostructures to confine the optical field and regulate carrier transport. These core–shell structures synergistically integrate and extend the functionalities of individual materials or devices. By integrating a p-type narrow-band Se material with an n-ZnO core, a 1D ZnO/Se core–shell radial heterojunction is fabricated for a self-powered broadband photodetector (PD). This 1D ZnO/Se core–shell radial heterostructure exhibits there main advantages: 1) forming a radial channel to make carriers transport more efficiently; 2) improving the efficiency of carrier transport and collection by introducing the high conductivity of Se layer; 3) passivating the surface defects of ZnO by Se shell layer. As a result, this core–shell radial heterojunction demonstrates high responsivity and detectivity across UV to visible light spectrum, with fast photoresponse times of 377/532 µs for rise/decay. These results revealed the superiority of 1D core–shell radial heterojunction in high-performance PDs, showing great potential for application in the development of advance optoelectronic devices.