Intrinsic microcrystalline silicon (μc-Si:H)-a promising newthin film solar cell material

“Compensated” microcrystalline silicon is obtained by adding 8-20 ppm diborane in the plasma gas phase. p-i-n cells with such i-layers have increased infrared sensitivity when compared to a-Si:H p-i-n cells. The preparation of the world's first “mixed stacked” a-Si:H/μc-Si:H tandem cell with an initial efficiency of 9.1% is reported. The μc-Si:H cells showed no degradation of the cell performance under intense light-soaking. Typical properties of the μc-Si:H cell indicate that the electronic transport is dominated by the crystalline phase of the material.