Pressure dependence of 2D hole mobility in thermoactivated photoconductivity effect observed in p‐GaAs/Al0.5Ga0.5As heterostructures

The temperature dependence of the 2D hole mobility in p-GaAs/Al 0.5 Ga 0.5 As heterostructures has been investigated in dark and illuminated with red light states under uniaxial compression up to 3.4 kbar in the temperature interval 1.5-20 K. From numerical calculations it has been shown that the decrease of the 2D hole mobility below 5.5 K, where the recently observed thermoactivated negative photoconductivity takes place, may be well described by scattering on ionized deep donor-like traps located in Al 0.5 Ga 0.5 As in the vicinity of a heterointerface. According to the calculations, these traps are distributed in the spacer at distances of 7-48 nm from the heterointerface and their contribution to 2D hole scattering strongly increases under uniaxial compression.