Ftir and UV Study of Amorphous Silicon-Boron Alloys Deposited by LPCVD

As-deposited and wet oxidized a-Si:B alloy deposited by low pressure chemical vapor deposition (LPCVD) with various boron content was studied by UV Spectroscopy and Fourier Transform Infrared Spectroscopy. It is found that the optical band gap of a-Si:B varies with respect to the boron content, which provides potential application probability in narrow-gap photovoltaic devices. This effect is associated with the structure change induced by B content. The oxidation behaviors of a-Si:B films with boron content 3 at.% – 25 at.% are different from those with boron content exceeded 30 at.%. Possible oxidation mechanism for different boron content a-Si:B film are proposed.