Deposition and Properties of Hydrogenated Microcrystalline Silicon (μc-Si:H) Films for Solar Cells

Abstract

Radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) technique is widely used in preparing uniform and large area a-Si:H films for various photoelectric devices. However, in the deposition processes of PECVD, the plasma bombardment to the deposited films will result in hindering the processes of crystallization. In the processes of hot-wire chemical vapor deposition (HWCVD), high-crystallinity films with a quickly growth rate can be obtained. In this article, hydrogenated microcrystalline silicon (μc-Si:H) films on glass substrate were prepared by a combination technique of HWCVD and RF inductively coupled plasma (ICP) at a low pressure (7Pa). The deposition parameters including the distance between the glass substrate with the hot wire and the flow ratio of SiH4/H2 in order to optimize the properties of μc-Si:H films. The crystallinity, microstructure, electrical and optical properties of the μc-Si:H films were investigated by Raman Spectroscopy, X-ray diffraction analysis (XRD), and UV-visible spectrometer, respectively. The results indicate that the crystallinity of the μc-Si:H films can be controlled at a very wide range and the deposition rate is up to 3nm/s. The deposited films show excellence electrical and optical properties.