Simulation of Impact Ionization Coefficients in InAlAs/InAsSb Type-II Superlattice Material Systems

We simulate transport for proposed low excess-noise avalanche photodiode InAlAs/InAsSb type-II superlattice materials to evaluate their impact ionization coefficients; a key metric in determining avalanche photodiode performance. The ensemble Monte Carlo method is utilized to develop a stochastic transport kernel suitable for superlattice transport in the static field approximation. The electronic band structure and impact ionization rates are computed from a 14-band superlattice envelope function $$\varvec{K}\cdot \varvec{p}$$ formalism. We reveal that band engineering through superlattice design can be utilized to enhance the electron-to-hole impact ionization ratio in the InAlAs/InAsSb superlattice material system.