MEASUREMENT OF THE IMPACT IONIZATION RATES IN AL0.06GA0.94SB

We measured impact ionization rates in AlxGa1-xSb at x=0.06, where the band-gap energy Eg equals the spin-orbital splitting energy Δ, in an electric field of 1.5×105-3.2×10 5 V/cm. By considering exact field profile in the depletion layer for each sample, the ionization rates of AlxGa1-xSb have been determined to be α=2.35×106 exp(-1.30×10 6/E) and β=9.02×105 exp(-9.03×10 5/E). Although our data have not shown the resonant enhancement of hole ionization rates described by O. Hildebrand, W. Kuebart, and M. Pilkuhn [Appl. Phys. Lett. 37, 801 (1980)], exact values of impact ionization rates have been established in practical electric fields required for designing Al xGa1-xSb avalanche photodiodes.