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

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.