Fig. 1. Schematic cross sections of (a) InAlAs APDs and (b) AlGaAs APDs.

Fig. 2. Excess noise factor, F⟨M⟩, of InAlAs digital and random alloy APDs.

Fig. 3. Excess noise factor, F⟨M⟩, of AlGaAs digital and random alloy APDs.

Fig. 4. (a) InAlAs digital and random alloy supercells, (b) positions in reciprocal space, (c) band structures of InAlAs random alloy at different positions, and (d) band structures of InAlAs digital alloy at different positions. The mini-gap in the valence band is marked.

Fig. 5. Temperature dependence of (a) excess noise factor and (b) ionization coefficient ratio k for InAlAs random alloy APD.

Fig. 6. Temperature dependence of (a) excess noise factor and (b) ionization coefficient ratio k for InAlAs digital alloy APD.

Fig. 7. Band structures of (a) AlGaAs random alloy and (b) AlGaAs digital alloy.

Fig. 8. Temperature dependence of (a) excess noise factor and (b) ionization coefficient ratio k for AlGaAs digital alloy p-i-n APD.

Fig. 9. Ionization coefficients of (a) InAlAs random alloy, (b) InAlAs digital alloy, and (c) AlGaAs digital alloy at different temperatures.

Fig. 10. Plots of Eqs. (7) and (8), the temperature-dependent ionization coefficients of the InAlAs digital alloy.