Visible photoluminescence from an anodized polycrystalline silicon thin film/silicon structure

Abstract

We measured visible photoluminescence and current-voltage from an electrochemically anodized polycrystalline silicon thin film/silicon structure. Room-temperature photoluminescence for the structure increases with the increase of the surface area of the interface between the polycrystalline silicon film and silicon substrate. Scaning Electron Microscopy images from the structures indicate that grain boundaries on the surface of polycrystalline thin film do the roles of passing channels of current during an electrochemical anodization process. With infrared data correlated with photoluminescence results, it is concluded that the photoluminescence from the polycrystalline silicon thin film/silicon structure origins from silicon hydrides adsorbed onto the interface between the film and substrate. Current-voltage was measured to understand electrical properties on Schottky-barrier devices fabricated with anodized polycrystalline silicon films. Current-voltage measurements resulted in a rectification behavior for the devices. The measurements suggest that the devices are mainly limited by series resistance due to electrochemically anodized layers in the poly-Si/Si Schottky device.