Study On Transitional Material Of Amorphous/Microcrystalline Silicon Thin Films Fabricated With VHF-PECVD

The transitional material of amorphous/microcrystalline silicon （a-Si: H/μc-Si: H）,because of its excellent optical characteristics of hydrogenated amorphous siliconmaterial（a-Si: H） and a stable structure of hydrogenated microcrystalline siliconmaterial（μc-Si: H）, it can be used as an ideal material for preparation silicon thin filmsolar cells.In this paper, the hydrogenated amorphous silicon/microcrystalline silicon （a-Si:H/μc-Si:H） thin films were prepared at different silane concentration, substratetemperature, discharge power and deposition pressure through very-high frequencyplasma chemical-vapor-deposition（VHF-PECVD）, for which to find the optimummanufacture condition under which could prepare the hydrogenated amorphoussilicon/microcrystalline silicon （a-Si:H/μc-Si:H） thin films that have both the excellentphotoelectric characteristics of amorphous silicon material and stable structure ofmicrocrystalline silicon material. The structural characteristics, optical properties andelectrical properties were studied by Raman scatting spectrum, ShimadzuSpectrophotometer UV-2550and Keithley2635SYSTEM Sourcemeter.The results showed that, with the increasing of silane concentration, substratetemperature, discharge power and deposition pressure, the deposition rate increasedaccordingly. Under the condition of silane concentration from2%to4%, substratetemperature from300℃to330℃, discharge powerfrom25W to35W and depositionpressure from80Pa to120Pa, we could obtain good quality hydrogenated amorphoussilicon/microcrystalline silicon （a-Si:H/μc-Si:H） transitional material, with a depositionrate of over0.25nm/s, optical band gap below1.7eV,10^-7-10^-5S/cm optical conductivity,10^-9-10^-5S/cm dark conductivity and10²-10³photosensitivity.