Optical-phonon scattering in quasi-two-dimensional heterojunction systems

The electronic scattering due to optical phonons in quasi-two-dimensional (Q2D) systems is investigated as a function of temperature. The three-dimensional (3D) Frohlich Hamiltonian (FH), a standard approximation to account for optical-phonon scattering in Q2D systems, is compared to two more realistic mechanisms that are available in the literature. These two mechanisms are due to Q2D electrons interacting with the interface as well as the half space bulk optical phonons. The results reveal that these two mechanisms combined give rise to a mobility that is slightly lower than that obtained with the 3D bulk FH. Additionally, a two-dimensional (2D) limit of the interface optical Hamiltonian gives rise to a much higher scattering than the pure 3D bulk via the FH.