The successful application of boron_doped hydrogenated nanocrystalline silicon a s window layer in a-Si∶H nip solar cells on stainless steel foil with a thickne ss of 005mm is reported. Open circuit voltage and fill factor of the fabricate d solar cell were 090V and 070 respectively. The optical and structural prop erties of the p-layers have been investigated by using UV-VIS and Raman spectros copy. It is confirmed that the p-layer is hydrogenated nanocrystalline silicon w ith a wide optical gap due to quantum size effect.