NEGF Modeling of Carrier Transport in Antimonide-based Type-II Superlattice Absorbers

Aiming at a rigorous description of optical absorption and carrier transport in broken-gap type-II superlattice absorbers, we employ a quantum-kinetic framework based on a nonequilibrium Green's function approach, with fully nonlocal carrier-phonon and carrier-photon self-energies computed within the self-consistent Born approximation. For a realistic description of the electronic structure, we express Green's functions and self-energies in a multiband multiband k · p basis within the envelope function approximation. We address the staggering cost of multiband NEGF models by transforming the kinetic equations from real space to a modal space spanned by numerically generated problem-matched basis functions. Inspection of energy-and position-resolved single particle properties such as carrier density and spectral current offers insight into the complex nature of carrier transport in broken-gap nanostructures.