Energy resolved ultrafast relaxation dynamics close to the band edge of low-temperature grown GaAs
نویسندگان
چکیده
We investigate the relaxation dynamics of photogenerated carriers in low-temperature grown GaAs by femtosecond pump-probe measurements. The carrier dynamics in the vicinity of the band edge is disentangled in a two-color technique. The filling of shallow bound states close beneath the band edge is resolved. A temporal delay in the occupation of these states as well as a large optical nonlinearity points towards microscopic potential fluctuations forming these states. © 1997 American Institute of Physics. @S0003-6951~97!00345-8#
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