Stable Amorphous Silicon and Improved Microcrystalline Silicon by Photon-Assisted Electron Cyclotron Resonance Chemical Vapor Deposition

Amorphous (a-Si) and microcrystalline silicon (μc-Si) are widely used in photovoltaics and thin film transistors. These products suffer from instability and less than desired electrical properties. We have utilized photon-assisted electron cyclotron resonance chemical vapor deposition (PA-ECRCVD) resulting in great improvement in both areas. For example, PA-ECRCVD compared with conventional ECR-CVD gives carrier lifetime of 1.35 4ts compared to 0.17 μs, and photovoltaic solar cell efficiency of 10 % compared to 5.9 %. Moreover, the PAECRCVD cell only degraded to 9.8 % compared to the ECR-CVD cell degradation to 5.5 %, under long term exposure to tungsten lamp illumination. In addition, PA-ECRCVD gives much enhanced crystallinity in μc-Si as revealed by atomic force microscopy and Raman spectroscopy.