3 August 1987 Picosecond Photomodulation Spectroscopy In Amorphous Semiconductors
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Proceedings Volume 0793, Ultrafast Laser Probe Phenomena in Bulk and Microstructure Semiconductors; (1987) https://doi.org/10.1117/12.940878
Event: Advances in Semiconductors and Semiconductor Structures, 1987, Bay Point, FL, United States
Picosecond trapping of photogenerated carriers in gap states of doped, compensated and undoped amorphous hydrogenated silicon (a-Si:H) and of a-Si:H based superlattices was studied by the pump and probe photomodulation technique. In undoped a-Si:H the photogenerated carriers are trapped in bandtail states and in compensated a-Si:H in impurity states introduced by doping. In singly doped a-Si:H the photoexcited majority carriers are trapped in impurity states whereas the photoexcited minority carriers are trapped in charged dangling bond defects. In a-Si:H/a-SiNx:H superlattices photocarriers are trapped in interface related defects. In all cases we found that electron trapping is about 50 times faster than hole trapping. This intrinsic property of a-Si:H originates from a larger electron hopping rate among localized states in the conduction band-tail.
© (1987) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Z. Vardeny, C. Thomsen, H. T. Grahn, J. Tauc, "Picosecond Photomodulation Spectroscopy In Amorphous Semiconductors", Proc. SPIE 0793, Ultrafast Laser Probe Phenomena in Bulk and Microstructure Semiconductors, (3 August 1987); doi: 10.1117/12.940878; https://doi.org/10.1117/12.940878

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