Experimental determination of hot‐carrier scattering processes in AlxGa1−xAs

The initial relaxation of hot electrons in Al0.35Ga0.65As has been measured using optical transmission‐correlation spectroscopy. In order to determine the contributions of distinct scattering processes, the kinetic energy of the photoexcited carriers was varied by temperature tuning the band gap of the material. We obtain the rates of intervalley scattering, carrier‐carrier scattering, and polar phonon emission from the measured decays. When scattering to the satellite (L and X) valleys is energetically possible, this process dominates the relaxation.