Highly conductive boron-doped nanocrystalline silicon-carbide film prepared by low-hydrogen-dilution photo-CVD method using ethylene as a carbon source

Abstract

Boron-doped nanocrystalline silicon-carbide (p-nc-SiC:H) films with a low-concentration of hydrogen-dilution were grown by a mercury-sensitized photo-chemical vapor deposition method using silane (SiH 4), hydrogen (H 2), diborane (B 2H 6), and ethylene (C 2H 4) as a carbon source. From the Raman and FTIR spectrum measurements, the p-nc-SiC:H film is composed of nanosize crystal silicon embedded in a hydrogenated amorphous silicon-carbide matrix. A dark conductivity as high as 1.7×10 −1 S/cm, with an optical bandgap is 2.0 eV, and a crystal volume fraction of 50%, were obtained. We tested these films as window material for amorphous silicon solar cells, obtaining an initial conversion efficiency of 10.4% without using any back reflectors.