Temperature dependence of minority-carrier mobility and recombination time in p-type GaAs

The electron mobility in p-type GaAs, μpe, has been determined as a function of temperature by measuring the common-emitter cutoff frequency, fT, of an AlGaAs/GaAs n-p-n heterojunction bipolar transistor. The base was 0.6 μm thick and it was doped with 4×10 18 cm-3 Be. The 300 K value of 1055 cm2/V s and 79 K value of 5000 cm2/V s for μpe are comparable to the previously measured values. The discrepancy with the calculated values is pointed out. The recombination lifetime is also measured as a function of temperature for minority carriers. The results agree reasonably well with the calculated radiative recominbation time.