ZnO/Al2O3/p-Si/Al2O3/CuO heterojunction NIR photodetector with inverted-pyramid light-trapping structure

Abstract Micro and nano light-trapping structures are widely applied to improve the performance of optoelectronic devices. In this work, inverted-pyramid light trapping texture on industrial-sized p-type silicon was prepared by a rapid and repeatable one-step room-temperature Cu-MACE process. On this basis, various TMOs (transition metal oxide)-Si heterojunction photodetectors (PDs) are fabricated by a low-temperature process. After careful comparison, a ZnO/Al2O3/p-Si/Al2O3/CuO heterojunction is selected as the ideal device structure, and the corresponding work mechanism is proposed. Finally, by optimizing the Al2O3 tunneling layers’ thickness, a high-performance NIR PD working at 980 nm and -5V bias stands out. The bifacial carrier selective transportation PD exhibits a considerable detectivity (5.56 × 1011 Jones) and a high responsivity (7.10 A/W). Our work will expand the application of inverted-pyramid textured silicon and will pave a road for mass fabrication of TMOs-Si heterojunction PD.