Improvements in the disilane plasma deposition of hydrogenated amorphous silicon solar cells

Abstract

The use of disilane (Si 2H 6) in the glow discharge deposition of the intrinsic layers of hydrogenated amorphous silicon (a-Si:H) solar cells offers the advantage of high deposition rates and therefore a large throughput for a production facility. However, fabricating efficient devices at high rates (1.5 – 2.0 nm s −) using Si 2H 6 is considerably more difficult than making them at low rates (0.10 – 0.30 nm s −1) using silane (SiH 4). Si 2H 6 is more prone to gas phase polymerization than is SiH 4, tending to generate an orange powder at the cathode of the glow discharge chamber. Using a dual-chamber system, cells have been fabricated at high rates from Si 2H 6 without powder formation, and they are compared with cells made from SiH 4 in the same system.