Deposition processes for high efficiency microcrystalline silicon solar cells

Examples of recent achievements in the preparation of microcrystalline silicon for solar cell application are shown. The requirements on the deposition process given by the needs to prepare material with an optimum phase mixture are demonstrated. A focus is on the VHF-PECVD technique in the high-power, high-pressure regime. The advantage of the HWCVD process for improved interface performance is shown. Introduction of a buffer layer allows one to apply a high deposition rate processes and to achieve record solar cell efficiencies of 10.3% for a single junction μc-Si:H pin.