Theory of Electron Transport in Semiconductor Devices
Abstract
Abstract:In modern electronic devices the mobility of electrons is principally determined bytheir interaction with the polar optical modes of the semiconductor crystal. A reliable account has to take into account the role of interfaces in nanostructures and the resultant hybridization of lattice modes in the presence of lattice dispersion. We have already studied the effects in a single heterostructure, a quantum well, a quantum wire and a quantum dot [1]. In particular, we have described the scattering rate in the single heterostructure [2]. This is an important rate for the determination of energy relaxation, but what is needed for mobility is the momentum relaxation rate, and this is not simply related to the scattering rate, due to the substantial energy of the optical phonon. We intend to use the ladder technique [3] to determine the mobility in a polar semiconductor. This requires us to go beyond the long-wavelength approximation. Consequently we need to determine the effect of the mixing of optical and acoustic modes towards short wavelengths. Another aspect that arises is the coherence of travelling lattice modes, for this is assumed in any hybridization, and we will examine what factors limit it and how the dimension of the crystal layer enters. In a limiting case, we notice that the total confinement of a lattice wave in the direction of the electron current removes its ability to relax momentum. We willcontinue to develop our Monte Carlo program to parallel analytical work and also for modeling thz generation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 10, 2018
- Source ID
- N000141812373
Entities
People
- Brian Kidd Ridley
Organizations
- Office of Naval Research
- United States Navy
- University of Essex