Fabrication of Polysilicon Thin-Film Solar Cells Using Hot-Wire Chemical Vapor Deposition

• Main Authors: Bing-Rui Wu, 吳秉叡
• Other Authors: Pin-Chuan Yao
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/98q8m6

碩士 === 大葉大學 === 電機工程學系碩士班 === 93 === Hot-Wire chemical vapor deposition is a promising technique for deposition of thin amorphous, polycrystalline silicon films for semiconductor device. In this method, deposition species are generated by the decomposition reaction of source gases on the heated metal wire. This technique related with the simple apparatus shows the advantage of low cost, high deposition rate and effective decomposition of reactive gases at low substrate temperature. In our experimentation, we produced poly-Si films by HWCVD with a high deposition rate faster than 0.8 nm/s. The crystalline fraction, evaluated by Raman spectroscopy, exceeds 93% for films on silicon wafer at a substrate temperature of 350 ℃. The grain size, estimated from scanning electron microscopy, was approximately 165 nm with a thickness of 1 um. And the H predominantly in the Si-2H bonding configuration for H contents as low as 1.3 at.%. Therefore, this properties of HWCVD poly-Si films was found to be promising in solar-cell applications. The spin-on diffusion technique, made by the combination of sol-gel process and thermal diffusion is proposed as an low-cost process for large area devices, like solar cells. In our experimentation, p-n junctions were formed using solid phase diffusion from phosphorous-doped spin-on dopant source with various thermal annealing conditions and various process time by conventional furnace . In this thesis, we report on our latest results in this techniques. We achieving initial and stable conversion efficiencies of 1.25 % for n-type poly-Si films thickness of 1μm by HWCVD and SOD techniques on p-type c-Si substrate. Open-circuit voltages consistently above 0.46 V.