skip to main content

Title: Optical properties of GaN pyramids

Picosecond time-resolved photoluminescence (PL) spectroscopy has been used to investigate the optical properties of GaN pyramids overgrown on hexagonal-patterned GaN(0001) epilayers on sapphire and silicon substrates with AlN buffer layers. We found that: (i) the release of the biaxial compressive strain in GaN pyramids on GaN/AlN/sapphire substrate led to a 7 meV redshift of the spectral peak position with respect to the strained GaN epilayer grown under identical conditions; (ii) in the GaN pyramids on GaN/AlN/sapphire substrate, strong band edge transitions with much narrower linewidths than those in the GaN epilayer have been observed, indicating the improved crystalline quality of the overgrown pyramids; (iii) PL spectra taken from different parts of the pyramids revealed that the top of the pyramid had the highest crystalline quality; and (iv) the presence of strong band-to-impurity transitions in the pyramids were primarily due to the incorporation of the oxygen and silicon impurities from the SiO{sub 2} mask. {copyright} {ital 1999 American Institute of Physics.}
Authors:
; ;  [1] ;  [2]
  1. Department of Physics, Kansas State University, Manhattan, Kansas 66506-2601 (United States)
  2. Honeywell Technology Center, 12001 State Highway 55, Plymouth, Minnesota 55441 (United States)
Publication Date:
OSTI Identifier:
321453
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 74; Journal Issue: 9; Other Information: PBD: Mar 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GALLIUM COMPOUNDS; RED SHIFT; GALLIUM NITRIDES; PHOTOLUMINESCENCE; STRAINS; CHEMICAL VAPOR DEPOSITION; ENERGY-LEVEL TRANSITIONS; SAPPHIRE; ALUMINIUM NITRIDES; CRYSTAL GROWTH; IMPURITIES