High density femtosecond excitation of nonthermal carrier distributions in intrinsic and modulation doped GaAs quantum wells
The dynamics of nonthermal carrier distributions is studied in undoped and modulation doped GaAs Quantum Well Structures (layer thickness is approximately 100 A) with near bandgap-resonant intense femtosecond light pulses. The carrier-carrier scattering process was studied up to very high energies, and the first optical investigation of nonthermal carrier generation in the presence of a thermalized Fermi-sea of electrons was performed. In undoped quantum wells a reduction of the thermalization time was found from about 100 fs to about 30 fs as the photocarrier density increases from N sub eh is approximately 3 x 10 to the 10th/sq cm to approximately 10 to the 12th/sq cm. The thermalization time is found to be sensitive to background doping with excess electrons in modulation doped samples.
- OSTI ID:
- 7004223
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360603* -- Materials-- Properties
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420300 -- Engineering-- Lasers-- (-1989)
ARSENIC COMPOUNDS
ARSENIDES
CHARGE DISTRIBUTION
DATA
DOPED MATERIALS
EXPERIMENTAL DATA
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INFORMATION
MATERIALS
MODULATION
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PNICTIDES
SCATTERING