Photovoltaic properties of boron-incorporated amorphous carbon on n-Si heterojunction grown by radio frequency plasma-enhanced chemical vapor deposition using trimethylboron

Boron-incorporated hydrogenated amorphous carbon (a-C:H) thin film, which is thought to be promising for p-type conductivity, on n-type Si(100) heterojunction photovoltaic devices has been grown by radio frequency plasma-enhanced chemical vapor deposition using trimethylboron. In order to identify the effect of boron incorporation, various CH₄ partial pressures have been examined. a-C:H/n-Si heterojunction solar cells with a conversion efficiency as high as 0.04% under 100 mW/cm² have been fabricated. The spectral response of cell photocurrents in the short wavelength region below 700 nm is determined to be due to the optical absorption of the boron incorporated a-C:H film. The photovoltaic properties of the a-C:H-based heterojunction solar cell structures are discussed with the dark and illuminated current density-voltage characteristics as well as the optical properties of boron-incorporated a-C:H film. The possibility of improving the conversion efficiency is also discussed.