Wide band-gap, fairly conductive p-type hydrogenated amorphous silicon carbide films prepared by direct photolysis; solar cell application

Abstract
Wide optical band‐gap (2.0–2.3 eV) undoped and boron‐doped hydrogenated amorphous silicon carbide (a‐SiC:H) films have been prepared by both direct photo and rf glow discharge (GD plasma) decomposition of pure methylsilanes or acetylene and disilane gas mixtures. The photochemically prepared p‐type films showed higher dark conductivities and lower activation energies. For an optical band gap of 2.0 eV a high conductivity of 7.0×105 (S cm1) and a low activation energy of 0.33 eV have been measured. The first trial of these wide band‐gap, fairly conductive films as a window layer in a pin solar cell showed the high conversion efficiency of 9.46% under AM1 insolation.