Application of p-type microcrystalline silicon to a-Si alloy solar cells

Detailed studies by the RHEED method have clearly indicated that microcrystalline silicon (/spl mu/c-Si:H) films prepared with a conventional RF p-CVD system can be deposited from the thickness of 10 nm even on a-SiC:H, a-SiGe:H alloy films and, furthermore, 25 nm-thick films have almost the same crystallinity as the 200 nm thick /spl mu/c-Si:H film. Application of this /spl mu/c-Si:H film to the p-layers of a-SiC:H and a-SiGe:H alloy solar cells have led to increases of 20/spl sim/40 mV in Voc, compared to typical a-SiC:H p-layer cells. Analysis of the diode saturation currents have showed that these increases of Voc were due to the increases of the built-in potential of the cells.