Unique characteristics of nonequilibrium carrier transport dynamics in an undoped GaAs-type GaAs epitaxial structure

摘要

We have investigated nonequilibrium carrier dynamics in an undoped GaAs-type GaAs epitaxial structure at room temperature using reflection-type pump-probe spectroscopy at different pump photon energies and Monte Carlo simulation. It was found that the transport process of photogenerated electrons in the undoped layer is characterized by the valance between the quasiballistic motion passing through the undoped layer and the intervalley scattering from the Gamma valley to the L one as a function of the excess energy of photogenerated electrons. The Gamma-L scattering component exhibits threshold-like appearance and then gradually increases with increasing excess energy. (C) 2016 The Japan Society of Applied Physics