Abstract
The femtosecond pump and probe technique with 2eV and 4eV photons was applied to the study of hot photocarriers with considerable excess energy in extended states of a-Si:H and a-Ge:H. Photoinduced changes in the complex dielectric constant ε1 + iε2 were calculated from the measured changes in reflectivity ΔR and transmission ΔT. This technique enables us to estimate that the average carrier cooling rates in our a-Si:H and a-Ge:H samples are about 2eV/psec and 1eV/psec, respectively. Photoinduced bleaching associated with the filling of band states dominates over intraband contributions to Δε1 and Δε2 for photon energies significantly exceeding the bandgap.
Original language | English (US) |
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Pages (from-to) | 531-534 |
Number of pages | 4 |
Journal | Journal of Non-Crystalline Solids |
Volume | 137-138 |
Issue number | PART 1 |
DOIs | |
State | Published - 1991 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry