Highly conductive p-type microcrystalline silicon thin layer is inserted between the front layer (ZnO:B) and the window layer(p-a-SiC) in a p-i-n amorphous silicon solar cell, and the inserted layer is found to be able to eliminate the non-ohmic contact, which is caused by the difference in the work function between the ZnO:B and p-a-SiC. The properties of the p-type microcrystalline silicon are studied by varying layer thickness, hydrogen dilution ratio and B2H6/SiH4 ratio. The optimized p-type microcrystalline silicon film can have a dark conductivity as large as 4.2 S/cm at a thickeness of 20 nm. The p-i-n type amorphous silicon solar cell with the p-type microcrystalline silicon is shown to have a good open circuit voltage and fill factor compared with without the p-type microcrystalline silicon layer.