Composition dependence of the hole mobility in GaSb_x As_1-x

The unusually low hole mobility observed in heavily p-type doped dilute GaSb_xAs_1-x alloys is explained in the context of the valence band anticrossing model. The anticrossing interaction between the localized p-states of the Sb atoms and the extended states of the GaAs host leads to a significant reconfiguration of the valence band structure and results in a greatly enhanced scattering of holes by state broadening effects in As-rich alloys. These results suggest that the mobility drop is fundamental in nature and indicate that the valence band anticrossing model is capable of describing the electronic transport properties of highly mismatched alloys. © 2008 American Institute of Physics.