We have studied time-resolved reflectivity changes induced by femtosecond laser pulses in a-Si and a-Si:H thin-films. By varying pump-power, we have identified a non-radiative recombination process which controls the free-carrier density, N, on a picosecond time scale for N>5 ×1018cm-3 in a-Si:H and >5×1019 cm-3 in a-Si. At lower carrier densities, transients are controlled by trapping of free-carriers.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry