Beyond the Band Minima: High Energy Electron Dispersion, Physics and Technology
Abstract
The field of semiconductor materials, devices and physics is built on an interplay betweentheory, modeling, simulation and experiment. For problems where the semiconductor is nearequilibrium, such as in low field transport, understanding the electronic structure near the bandextrema, electron-phonon coupling, and dielectric properties are often sufficient to interpretexperimental data and model the material behavior. However, there are a wide range of processesthat generate hot carriers including high field transport, vertical transport in heterostructures,absorption of high energy photons, and internal Auger processes. The hot carriers may transfer todifferent valleys, cause impact ionization, and play a strong role in device lifetime and reliability.Understanding so many of these hot carrier processes depends on poorly known high energy bandstructure, particularly in the conduction band (CB), and poorly understood mechanisms anddynamics of energy gain or dissipation of hot carriers.This proposal is based on new experimental methods to determine the conduction bandelectronic dispersion E(k) and to reveal hot carrier processes: (i) Angle Resolved ElectronEmission Spectroscopy (AR-EES); (ii) Angle Resolved Reflected Electron Spectroscopy(ARRES); and (iii) Inelastic X-Ray Scattering (IXS) for interband transitions.The PI proposes to work on two materials systems for the VBFF program: (i) the group IIINitrides (GaN, AlN, InN and their alloys) as they are already the enabling materials system for RFtransistors for military radar; and (ii) the emerging ultrawidebandgap semiconductor beta-Ga2O3which shows remarkable promise for energy efficient power electronics for DoD systems. Theseare both important systems for experimentally determining the conduction band E(k) as there arehigh fields in both RF and power devices. The in situ AR-EES measurements will reveal thecarrier physics at high fields.As an educational institution, UCSB performs fundamentaland unclassified research. Any dataor information developed or provided by UCSB, including but not limited to publication andreports, shall be unclassified fundamental research exempt from dissemination controls or reviewrequirements.Approved for public release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 14, 2024
- Source ID
- N000142512040
Entities
People
- James A. Speck
Organizations
- Office of Naval Research
- United States Navy
- University of California, Santa Barbara