Temperature dependence of hole mobility in GaAs1−xBix alloys

The Hall mobility of holes has been measured in GaAs grown at low temperatures and in GaAs1−xBix alloys for Bi concentrations x ranging from 0.94% to 5.5%. The hole mobility is found to decrease with increasing Bi content. The temperature dependence of the mobility in the 25 to 300 K range is fit with a combination of phonon scattering, ionized impurity scattering, and Bi related scattering. The hole scattering cross-section for an isolated Bi impurity is estimated to be 0.2 nm2. The temperature independent mobility at the highest Bi concentration (x=5.5%), is interpreted as being limited by scattering from Bi clusters.