A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process an...A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process and the silicon thin films are studied by using optical emission spectroscopy （OES） and Fourier transfer infrared （FTIR） spectroscopy, respectively. The results show that when the silane concentration changes from 10% to 1%, the peak frequency of the Si-H stretching mode shifts from 2000 cm-1 to 2100 cm-1, while the peak frequency of the Si-H wagging-rocking mode shifts from 650 cm-1 to 620 cm-1. At the same time the SiH^＊/Ha intensity ratio in the plasma decreases gradually. The evolution of the infrared spectra and the optical emission spectra demonstrates a morphological phase transition from amorphous silicon （a-Si：H） to microcrystalline silicon （μc-Si：H）. The structural evolution and the p-c-SiH formation have been analyzed based on the variation of Ha and SiH^＊ intensities in the plasma. The role of oxygen impurity during the plasma process and in the silicon films is also discussed in this study.展开更多
Several diamidodisilanes and azocyclosilane were prepared from the resultants of Wurtz coupling reaction between dichlorosilane and sodium and characterized by 1H NMR and FT-IR. The two split peaks of the stretching v...Several diamidodisilanes and azocyclosilane were prepared from the resultants of Wurtz coupling reaction between dichlorosilane and sodium and characterized by 1H NMR and FT-IR. The two split peaks of the stretching vibration bonds of Si-H bonds in compounds 1 and 3 were firstly found at ～2163 cm-1 and ～2100 cm-1 respectively. The density functional theory was adopted to calculate the several stable geometrical isomerism structures of compounds 1 and 3. The results of the calculations show that the peak split of Si-H bonds stretching vibration absorption was caused by the different geometrical isomers of the compounds and the calculated IR spectra of compounds 1 and 3 are much closer to the experimental results. The processes of hydrolysis and polycondensation reactions of the synthetic compounds were studied by FT-IR. At the same time, the transition of Si-H bonds split peaks was observed in this procedure. As the results of the hydrolysis and condensation reactions, a new type of organic silicon polymer, polyoxydisilane was obtained, which presents the photoluminescence of the polysilanes.展开更多
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA050602)the International Cooperation Project between China-Greece Government (Grant No. 2009DFA62580)the National Basic Research Program of China (Grant Nos. 2011CBA00705, 2011CBA00706, and 2011CBA00707)
文摘A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process and the silicon thin films are studied by using optical emission spectroscopy （OES） and Fourier transfer infrared （FTIR） spectroscopy, respectively. The results show that when the silane concentration changes from 10% to 1%, the peak frequency of the Si-H stretching mode shifts from 2000 cm-1 to 2100 cm-1, while the peak frequency of the Si-H wagging-rocking mode shifts from 650 cm-1 to 620 cm-1. At the same time the SiH^＊/Ha intensity ratio in the plasma decreases gradually. The evolution of the infrared spectra and the optical emission spectra demonstrates a morphological phase transition from amorphous silicon （a-Si：H） to microcrystalline silicon （μc-Si：H）. The structural evolution and the p-c-SiH formation have been analyzed based on the variation of Ha and SiH^＊ intensities in the plasma. The role of oxygen impurity during the plasma process and in the silicon films is also discussed in this study.
基金This work was supported by the Key Science and Technology Project of Shanghai(Grant No.02dzI1002).
文摘Several diamidodisilanes and azocyclosilane were prepared from the resultants of Wurtz coupling reaction between dichlorosilane and sodium and characterized by 1H NMR and FT-IR. The two split peaks of the stretching vibration bonds of Si-H bonds in compounds 1 and 3 were firstly found at ～2163 cm-1 and ～2100 cm-1 respectively. The density functional theory was adopted to calculate the several stable geometrical isomerism structures of compounds 1 and 3. The results of the calculations show that the peak split of Si-H bonds stretching vibration absorption was caused by the different geometrical isomers of the compounds and the calculated IR spectra of compounds 1 and 3 are much closer to the experimental results. The processes of hydrolysis and polycondensation reactions of the synthetic compounds were studied by FT-IR. At the same time, the transition of Si-H bonds split peaks was observed in this procedure. As the results of the hydrolysis and condensation reactions, a new type of organic silicon polymer, polyoxydisilane was obtained, which presents the photoluminescence of the polysilanes.
