Influence of silane injection ways on optical emission spectroscopy and microstructure of microcrystalline silicon thin film

The microcrystalline silicon thin films and solar cells were deposited using very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The growth process of intrinsic microcrystalline silicon thin films deposited with different SiH4 injection ways was online monitored by optical emission spectroscopy. The results show that using the silane profiling injection way is better than the other two injection ways in the film growth. During the thin film growth process, the emission intensity of Hα*, Hβ* and SiH* shows an increase tendency, and the higher ratio of Hα*/SiH* in the initial deposition stage can contribute to the formation of high quality interfacial layer. Using this way, a significant improvement in the solar cell performance is achieved. A high conversion efficiency of 7.81% is obtained for a single-junction microcrystalline silicon solar cell at the deposition rate of 1 nm/s. ©, 2015, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.