Electrical properties of ZnO:H films fabricated by RF sputtering deposition and fabrication of p-NiO/n-ZnO heterojunction devices

A high-transparency ZnO thin film of high carrier concentration was grown by conventional RF sputtering, where the carrier concentration was continuously varied from 10(16) to 10(19) cm(-3) by controlling the amounts of O-2 and H-2 sputtering gases. To prevent the formation of a Schottky junction at the contact with In-Zn-O, and to improve the fill factor of a visible-light-transparent solar cell, a Ag-paste/NiO/ZnO/ZnO:H/IZO p-n diode structure with the carrier concentration of the ZnO:H layer of 10(19)cm(-3) was fabricated. It is possible to reduce the depletion width and inverse the rectification action around ZnO/IZO by controlling the carrier concentration of the ZnO layer while maintaining the high transparency. (c) 2018 The Japan Society of Applied Physics.