Impact ionization rates for electrons and holes in GaAs1−xSbx alloys

We have measured the impact ionization rates for electrons and holes in GaAs1−xSbx for alloys with x=0.05, 0.10, and 0.12. The results show that the ionization rates for electrons (α) and holes (β) are different and a function of Sb content. In particular, for GaAs0.88Sb0.12 electrons have the higher ionization rate with α/β=2.5, while for GaAs holes have the higher ionization rate with α/β=0.25.