Electron mobility in p-type GaAs

The mobility of electrons in p-type GaAs, μnP has been determined by measuring the common emitter cutoff frequency fT of heterojunction bipolar transistors with a wide, uniformly doped base. At 295 K, μnP =1150 cm2/(V s) is found for a hole concentration of 3.6×1018 cm-3. At 77 K, μnP =6000 cm2/(V s). The room-temperature value is considerably smaller and the 77 K value considerably larger than the electron mobility in comparably doped n-type material.