Self-Powered Photodetectors Based on Core–Shell ZnO–Co3O4 Nanowire Heterojunctions

• DOI: 10.1021/acsami.9b04838
• Publication Date: 2019-06-07T12:02:27Z
• Authors: Pedram Ghamgosar; Federica Rigoni; Mojtaba Gilzad Kohan; Shujie You; Edgar Abarca Morales; Raffaello Mazzaro; Vittorio Morandi; Nils Almqvist; Isabella Concina; Alberto Vomiero
• Keywords: Specific detectivity; Charge carrier; Visible spectrum

Self-powered photodetectors operating in the UV-visible-NIR window made of environmentally friendly, earth abundant, and cheap materials are appealing systems to exploit natural solar radiation without external power sources. In this study, we propose a new p-n junction nanostructure, based on ZnO-Co3O4 core-shell nanowire (NW) system, with suitable electronic band structure improved light absorption, charge transport, collection, build an efficient heterojunction photodetector. Ultrathin Co3O4 films (in range 1-15 nm) were sputter-deposited hydrothermally grown ZnO NW arrays. The effect thin layer Al2O3 buffer between was investigated, which may inhibit recombination, boosting device performance. photoresponse ZnO-Al2O3-Co3O4 system at zero bias is 6 times higher compared that ZnO-Co3O4. responsivity ( R) specific detectivity D*) best 21.80 mA W-1 4.12 × 1012 Jones, respectively. These results suggest novel develop all-oxide UV-vis stable, nontoxic, low-cost materials.