Subpicosecond carrier dynamics in low-temperature grown GaAs as measured by time-resolved terahertz spectroscopy

Matthew C. Beard, Gordon M. Turner, Charles A. Schmuttenmaer
2001 Journal of Applied Physics  
The transient photoconductivity in a 1 m layer of low temperature grown GaAs ͑LT-GaAs͒ on a GaAs substrate was measured using time-resolved terahertz spectroscopy. When photoexcitation occurs at 400 nm we find a time-dependent mobility that increases from 400Ϯ100 to 1100 Ϯ100 cm 2 V Ϫ1 s Ϫ1 with a time constant of 2 ps. Photoexcitation at 800 nm produces a time-independent mobility of 3000Ϯ500 cm 2 V Ϫ1 s Ϫ1 . We determine the carrier lifetime in LT-GaAs to be 1.1 Ϯ 0.1 ps.
doi:10.1063/1.1416140 fatcat:so2qah7ocbbuhnkpgqdomug5ie