Ultrafast carrier trapping in microcrystalline silicon observed in opticalpump-terahertz probe measurements

Citation
Pu. Jepsen et al., Ultrafast carrier trapping in microcrystalline silicon observed in opticalpump-terahertz probe measurements, APPL PHYS L, 79(9), 2001, pp. 1291-1293
Citations number
16
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
79
Issue
9
Year of publication
2001
Pages
1291 - 1293
Database
ISI
SICI code
0003-6951(20010827)79:9<1291:UCTIMS>2.0.ZU;2-C
Abstract
We report on direct evidence of ultrafast carrier dynamics displaying featu res on the picosecond time scale in microcrystalline silicon (muc-Si:H). Th e dynamics of photogenerated carriers is studied by using above-band-gap op tical excitation and probing the instantaneous carrier mobility and density with a THz pulse. Within the first picoseconds after excitation, the THz t ransmission transients show a fast initial decay of the photoinduced absorp tion followed by a slower decrease due to carrier recombination. We propose that the initial fast decay in the THz transients is due to carrier captur e in the trapping states. (C) 2001 American Institute of Physics.