PHONON-ASSISTED TUNNELING FROM A 2-DIMENSIONAL EMITTER STATE

We present a theory of phonon-assisted tunneling in GaAs/AlAs double-b arrier structures, which. treats the electrons in the emitter as a two -dimensional electron gas. A complete set of confined and interface op tical-phonon modes is calculated using a dielectric-continuum model, a nd we derive a general expression for the electron-phonon Hamiltonian valid for all optical-phonon modes in an arbitrary heterostructure. Th e electronic wave functions relevant to phonon-assisted tunneling are found by self-consistently solving the Schrodinger and Poisson equatio ns in both the well and the emitter. Five different phonon modes are p redicted to dominate the phonon-assisted tunneling current: three LO-l ike interface modes, the half-space modes in the emitter, and the conf ined modes in the well.