Hydrostatic pressure effect of photocarrier dynamics in GaAs probed by time-resolved terahertz spectroscopy

Hydrostatic pressure effects on photocarrier dynamics containing interband relaxations and intraband cooling in GaAs have been investigated using in situ time-resolved terahertz spectroscopy with a diamond anvil cell. The interband photocarrier lifetime significantly decreases by nearly two orders of magnitude under 10 GPa. Considerable pressure tuning for the intervalley scattering processes has also been observed, and the time constants under different pressures are extracted based on the three-state rate equation. This work provides new perspectives on tailoring nonequilibrium carrier dynamics in semiconductors using hydrostatic pressure and may serve as the impetus for the development of high-pressure THz spectroscopy.