skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride

Abstract

Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

Authors:
;  [1]
  1. Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)
Publication Date:
OSTI Identifier:
22486301
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 107; Journal Issue: 26; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BRILLOUIN ZONES; CARRIER DENSITY; COLLISIONS; ELASTIC SCATTERING; ELECTRON DENSITY; ELECTRON MOBILITY; ELECTRON TEMPERATURE; ELECTRONS; GALLIUM NITRIDES; MICROWAVE RADIATION; NOISE; PHONONS; SATURATION; TIME RESOLUTION; TRANSISTORS

Citation Formats

Khurgin, Jacob B., E-mail: jakek@jhu.edu, Bajaj, Sanyam, and Rajan, Siddharth. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride. United States: N. p., 2015. Web. doi:10.1063/1.4938745.
Khurgin, Jacob B., E-mail: jakek@jhu.edu, Bajaj, Sanyam, & Rajan, Siddharth. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride. United States. https://doi.org/10.1063/1.4938745
Khurgin, Jacob B., E-mail: jakek@jhu.edu, Bajaj, Sanyam, and Rajan, Siddharth. 2015. "Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride". United States. https://doi.org/10.1063/1.4938745.
@article{osti_22486301,
title = {Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride},
author = {Khurgin, Jacob B., E-mail: jakek@jhu.edu and Bajaj, Sanyam and Rajan, Siddharth},
abstractNote = {Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.},
doi = {10.1063/1.4938745},
url = {https://www.osti.gov/biblio/22486301}, journal = {Applied Physics Letters},
issn = {0003-6951},
number = 26,
volume = 107,
place = {United States},
year = {Mon Dec 28 00:00:00 EST 2015},
month = {Mon Dec 28 00:00:00 EST 2015}
}