A unique strategy for improving top contact in Si/ZnO hierarchical nanoheterostructure photodetectors

Abstract

Three-dimensional p-Si nanopillar/n-ZnO nanowire-array hierarchical nanoheterostructure photodetectors were achieved via a highly accessible and controllable fabrication process. By introducing PMMA to provide a flat, continuous and uniform surface, unique high transparency, low resistance top contact has been fabricated. The improved front electrode showed very small sheet resistivity of 0.002 Ω cm, two orders of magnitude lower than that of direct deposition of ITO onto ZnO (0.58 Ω cm).