Defects in amorphous silicon probed by subpicosecond photocarrier dynamics
- 6 April 1992
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 60 (14) , 1688-1690
- https://doi.org/10.1063/1.107212
Abstract
The photocarrier dynamics in pure nonhydrogenated amorphous silicon (a-Si) have been studied with subpicosecond resolution using pump-probe reflectivity measurements. The photocarrier lifetime increases with the annealing temperature from 1 ps for as-implanted a-Si to 11 ps for a-Si annealed at 500 °C. The lifetime in annealed a-Si can be returned to the as-implanted level by ion irradiation. These observations indicate that a-Si can accommodate a variable number of defect-related trapping and recombination centers. The saturated defect density in as-implanted a-Si is estimated to be ≊1.6 at. %. Comparison with Raman spectroscopy suggests that various kinds of structural defects are present in a-Si.Keywords
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