Off-center electron transport in resonant tunneling diodes due to incoherent scattering

Coherent transport through resonant tunneling diodes at high bias is determined by the transfer of carriers described by momentum and energy from a bath in the emitter through a central resonance to the collector. Simplified treatments of coherent carrier transport assume the transverse carrier dispersions to be identical and parabolic in the emitter and central device. This results in a carrier transport that is dominated by carriers at the G zone center. Other work has shown that more realistic dispersions result in off-zone center current flow. Incoherent scattering adds more degrees of freedom to match the emitter energy and momentum (Eem ,kem) with the resonance energy and momentum (Eres ,kres) with (DEscatt ,Dkscatt). It is shown analytically and numerically that this additional degree of freedom redirects carriers in energy and momentum space resulting in an off-zone center current for large voltage regions. Interface roughness, polar optical phonon, and acoustic phonon scatterings are explicitly considered.