Study of Microcrystalline Silicon Thin Films Deposited by Cat-CVD for Thin Film Solar Cell Applications
|關鍵字:||微晶矽;薄膜太陽能電池;結晶度;熱阻絲氣相沉積法;觸媒化學氣相沈積法;microcrystalline;thin film solar cell;crystallinity;catalytic chemical vapor;CAT-CVD;HWCVD|
In this study, Catalytic Chemical Vapor Deposition (Cat-CVD, also known as Hot-Wire Chemical Vapor Deposition, HWCVD) was used as the process equipment. The gases of silane (SiH4) and hydrogen (H2) were used to deposit hydrogenated microcrystalline film. In this thesis, the filament temperature and substrate temperature were calibrated at first. Then, by varying hydrogen-to-silane dilution ratio, process pressure, filament-to-substrate distance and different substrates, we have obtained the characteristics of the undoped microcrystalline silicon thin film. Also, we incorporated the undoped film into microcrystalline silicon thin film solar cell as an absorber, investigating the relationship between the thin film characteristics and device conversion efficiency. In microcrystalline silicon thin film, crystallinity is one of the most important characteristics. By conducting series of experiments, we have found that by enhancing hydrogen-to-silane dilution ratio, lowering process pressure, shortening the filament-to-substrate distance and using particular substrates would promote the crystallinity. The corresponding electrical characteristics and bonding composition were also discussed. Besides, substrate temperature played an essential role in device performance. Setting higher substrate temperature and longer pre-heating time by filament could effectively improved fill factor, making the conversion efficiency achieve 2.93%.
|Appears in Collections:||Thesis|