Title :
Picosecond carrier dynamics in a-Si0.5Ge0.5:H measured with a free-electron laser
Author :
Fauchet, Philippe M. ; Young, Daniel A. ; Nighan, William L., Jr. ; Fortmann, Charles M.
Author_Institution :
Dept. of Electr. Eng., Rochester Univ., NY, USA
fDate :
12/1/1991 12:00:00 AM
Abstract :
A picosecond time-resolved pump and probe experiment has been performed on a thin a-Si0.5Ge0.5:H film using the short optical pulses generated by the superconducting accelerator-pumped free-electron laser (FEL) at Stanford University. The FEL was tuned at 1.5 μm. The probe beam was at the fundamental wavelength, and the pump beam was obtained after frequency doubling. The authors found that the transmission decreases due to photogeneration of carriers and then recovers on a 6 ps time scale. This recovery is the signature of ultrafast carrier recombination. It is faster than in a-Si:H for similar conditions. A possible origin of the difference is discussed
Keywords :
Ge-Si alloys; amorphous semiconductors; carrier lifetime; free electron lasers; hydrogen; infrared spectra of inorganic solids; semiconductor thin films; time resolved spectra; 1.5 micron; FEL; Stanford University; amorphous Si0.5Ge0.5:H; carrier photogeneration; free-electron laser; frequency doubling; fundamental wavelength; picosecond carrier dynamics; picosecond time-resolved pump and probe experiment; probe beam; pump beam; semiconductor; short optical pulses; superconducting accelerator-pumped free-electron laser; thin a-Si0.5Ge0.5:H film; transmission; ultrafast carrier recombination; Acceleration; Free electron lasers; Laser beams; Laser excitation; Laser tuning; Optical films; Optical pulse generation; Optical pulses; Probes; Superconducting films;
Journal_Title :
Quantum Electronics, IEEE Journal of
