The dependence of the optical energies on InGaN composition
O'Donnell, KP × Martin, RW Trager-Cowan, C White, ME Esona, K Deatcher, C Middleton, PG Jacobs, K Van der Stricht, W Merlet, C Gil, B Vantomme, André Mosselmans, JFW #
Elsevier science sa
Materials science and engineering b-solid state materials for advanced technology vol:82 issue:1-3 pages:194-196
A nide-ranging experimental approach reveals a linear relationship between photoluminescence band peak energy and measured indium fraction for InxGa1-xN epilayers with 0 < x < 0.40. We examine the dependence of the emission spectrum on composition using local measurements of the average indium content by Rutherford backscattering spectrometry, energy dispersive X-ray analysis, extended X-ray absorption fine structure and wavelength dispersed electron probe micro-analysis. Corresponding absorption and photoluminescence excitation data reveal the existence of a supplementary linear relationship between the optical bandgap and the indium fraction. Our observations provide definitive and conclusive evidence that the optical properties of InGaN do not conform to current theoretical descriptions of alloy band structure. (C) 2001 Elsevier Science B.V. All rights reserved.