Boron doping in a-SiO:H,

Abstract

Boron-doping characteristics in hydrogenated amorphous silicon–oxygen alloys (a-SiO:H) have been studied in contrast to those in hydrogenated amorphous silicon (a-Si:H). Although the boron-incorporation efficiency shows almost the same value between a-SiO:H and a-Si:H, p-type a-SiO:H (p-a-SiO:H) exhibits lower dark conductivity by one or two orders of magnitude as compared to p-type a-Si:H (p-a-Si:H) in a wide range of doping levels. We have found that p-a-SiO:H exhibits low dark conductivity as compared to p-a-Si:H even when we choose samples showing the same activation energy from a variety of as-deposited and thermally annealed samples. We have concluded from the different Urbach-energy values between high quality intrinsic a-SiO:H and a-Si:H that the origin of low dark conductivity in p-a-SiO:H is due to low hole mobility.