skip to main content

SciTech ConnectSciTech Connect

Title: Strain dependence on polarization properties of AlGaN and AlGaN-based ultraviolet lasers grown on AlN substrates

Since the band ordering in AlGaN has a profound effect on the performance of UVC light emitting diodes (LEDs) and even determines the feasibility of surface emitting lasers, the polarization properties of emitted light from c-oriented AlGaN and AlGaN-based laser structures were studied over the whole composition range, as well as various strain states, quantum confinements, and carrier densities. A quantitative relationship between the theoretical valence band separation, determined using k•p theory, and the experimentally measured degree of polarization is presented. Next to composition, strain was found to have the largest influence on the degree of polarization while all other factors were practically insignificant. The lowest crossover point from the transverse electric to transverse magnetic polarized emission of 245 nm was found for structures pseudomorphically grown on AlN substrates. This finding has significant implications toward the efficiency and feasibility of surface emitting devices below this wavelength.
Authors:
; ; ;  [1] ;  [2] ;  [3]
  1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)
  2. HexaTech, Inc., 991 Aviation Pkwy., Suite 800, Morrisville, North Carolina 27560 (United States)
  3. Adroit Materials, 2054 Kildaire Farm Rd., Suite 205, Cary, North Carolina 27518 (United States)
Publication Date:
OSTI Identifier:
22412553
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM NITRIDES; CARRIER DENSITY; EFFICIENCY; GALLIUM NITRIDES; LASERS; LIGHT EMITTING DIODES; POLARIZATION; STRAINS; SUBSTRATES; ULTRAVIOLET RADIATION