Ag2S/ZnO core-shell nanoheterojunction for a self-powered solid-state photodetector with wide spectral response

On the face of the impending energy crisis, developing low-energy consuming photoelectronic devices is extremely important. A wide spectral photosensitivity feature of a self-powered device provides an additional powerful tool. In this letter, a Ag2S/ZnO core-shell nanoheterojunction was prepared and a high performance self-powered solid-state photodetector was developed based on this nanostructure. High quality, vertically aligned ZnO nanoneedle arrays loaded with Ag2S quantum dotes were grown on FTO glass substrate by wet chemical methods. The microstructure and surface morphology of the prepared samples were characterized by transmission electron microscopy and scanning electron microscopy. A solid-state self-powered photodetector was assembled using this ZnO/Ag2S core-shell nanostructure as the photoanode. The photodetector shows a high photosensitivity in the wide spectral range from 400 to 1100 nm, and its response time is as short as 5 ms. Considering its excellent performance and easy fabrication process, this Ag2S/ZnO core-shell nanoheterojunction is an ideal candidate for wide spectral photodetecting application. (C) 2017 Elsevier B.V. All rights reserved.