Nonequilibrium Green’s-function method applied to double-barrier resonant-tunneling diodes

Abstract

The effect of inelastic scattering on quantum electron transport through double-barrier resonant-tunneling structures with large cross-sectional areas is studied numerically using the approach based on the nonequilibrium Green’s-function formalism of Keldysh, Kadanoff, and Baym. The Markov assumption is not made, and the energy coordinate is retained. This makes the inclusion of the phonon-energy spectrum straightforward both conceptually and in practice. The electron-phonon interaction is treated in the self-consistent first Born approximation (SCFBA). The Pauli exclusion principle is taken into account exactly within the SCFBA. The retention of the energy coordinate allows the calculation of a number of quantities that give insight into the effect of inelastic scattering on electron transport: The effect of inelastic scattering on the occupation of the energy levels, the density of states, the energy distribution of the current density, and the power density is calculated from a quantum kinetic equation for actual device structures under high bias.