Ultrafast carrier trapping in microcrystalline silicon observed in optical pump–terahertz probe measurements
| Autor: | Klaus Lips, I. H. Libon, M. Schall, P. Uhd Jepsen, N. E. Hecker, Uli Lemmer, Mario Birkholz, W. Schairer |
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| Rok vydání: | 2001 |
| Předmět: |
Electron mobility
Materials science Physics and Astronomy (miscellaneous) Silicon Terahertz radiation business.industry Photoconductivity Physics::Optics chemistry.chemical_element Optical pumping Condensed Matter::Materials Science chemistry Picosecond Optoelectronics business Ultrashort pulse Excitation |
| Zdroj: | Technical University of Denmark Orbit |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/1.1394953 |
| Popis: | We report on direct evidence of ultrafast carrier dynamics displaying features on the picosecond time scale in microcrystalline silicon (μc-Si:H). The dynamics of photogenerated carriers is studied by using above-band-gap optical excitation and probing the instantaneous carrier mobility and density with a THz pulse. Within the first picoseconds after excitation, the THz transmission transients show a fast initial decay of the photoinduced absorption followed by a slower decrease due to carrier recombination. We propose that the initial fast decay in the THz transients is due to carrier capture in the trapping states. |
| Databáze: | OpenAIRE |
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