摘要
Intrinsic hydrogenated microcrystalline silicon （μc-Si：H） films have been prepared by hot-wire-assisted microwave electron-cyclotron-resonance chemical vapour deposition （HW-MWECR-CVD） under different deposition conditions, Fourier-transform infrared spectra and Raman spectra were measured. Optical band gap was determined by Tauc plots, and experiments of photo-induced degradation were performed. It was observed that hydrogen dilution plays a more essential role than substrate temperature in microcrystalline transformation at low temperatures. Crystalline volume fraction and mean grain size in the films increase with the dilution ratio （R=H2/（H2＋SiH4））. With the rise of crystallinity in the films, the optical band gap tends to become narrower while the hydrogen content and photo-induced degradation decrease dramatically. The samples, were identified as μc-Si：H films, by calculating the optical band gap. It is considered that hydrogen dilution has an effect on reducing the crystallization activation energy of the material, which promotes the heterogeneous solid-state phase transition characterized by the Johnson-Mehl-Avrami （JMA） equation. The films with the needed structure can be prepared by balancing deposition and crystallization through controlling process parameters.
Intrinsic hydrogenated microcrystalline silicon （μc-Si：H） films have been prepared by hot-wire-assisted microwave electron-cyclotron-resonance chemical vapour deposition （HW-MWECR-CVD） under different deposition conditions, Fourier-transform infrared spectra and Raman spectra were measured. Optical band gap was determined by Tauc plots, and experiments of photo-induced degradation were performed. It was observed that hydrogen dilution plays a more essential role than substrate temperature in microcrystalline transformation at low temperatures. Crystalline volume fraction and mean grain size in the films increase with the dilution ratio （R=H2/（H2＋SiH4））. With the rise of crystallinity in the films, the optical band gap tends to become narrower while the hydrogen content and photo-induced degradation decrease dramatically. The samples, were identified as μc-Si：H films, by calculating the optical band gap. It is considered that hydrogen dilution has an effect on reducing the crystallization activation energy of the material, which promotes the heterogeneous solid-state phase transition characterized by the Johnson-Mehl-Avrami （JMA） equation. The films with the needed structure can be prepared by balancing deposition and crystallization through controlling process parameters.
