Fabrication of amorphous silicon carbide films using VHF-PECVD for triple-junction thin-film solar cell applications

Preparation of intrinsic hydrogenated amorphous silicon carbide (i-a-SiC:H) thin films for use as a top cell of triple junction solar cells is presented. These films were deposited using very-high-frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) technique with monomethyl silane (MMS) gas as the carbon source. Deposition conditions were explored to obtain films with a wide gap and low defect density. It was confirmed that the hydrogen dilution ratio plays an important role in enhancing the film properties. Employing a-SiC:H film as an intrinsic layer of single junction cell, open-circuit voltage as high as 0.99 V has been achieved.