Photoluminescence of InNAs alloys: S-shaped temperature dependence and conduction-band nonparabolicity

Merrick, M., Cripps, S. A., Murdin, B. N., Hosea, T.J. C., Veal, T. D., McConville, C. F. and Hopkinson, M. (2007) Photoluminescence of InNAs alloys: S-shaped temperature dependence and conduction-band nonparabolicity Physical Review B, 76 (075209). ISSN 1098-0121

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Abstract

Photoluminescence (PL) has been used as a means of unambiguously observing band gap reduction in InNAs epilayers grown by molecular beam epitaxy. The observed redshift in room temperature emission as a function of nitrogen concentration is in agreement with the predictions of the band anticrossing (BAC) model, as implemented with model parameters derived from tight-binding calculations. The temperature dependence of the emission from certain samples exhibits a signature non-Varshni-like behavior indicative of electron trapping in nitrogen-related localized states below the conduction-band edge, as predicted by the linear combination of isolated nitrogen states (LCINS) model. This non-Varshni-like behavior tends to grow more pronounced with increasing nitrogen content, but for the highest nitrogen concentration studied, the more familiar Varshni-like behavior is recovered. Although unexpected, this observation is found to be consistent with the BAC and LCINS models. With consideration given to the effects of conduction-band nonparabolicity on the emission line shapes, the BAC model parameters extracted from the measured PL transition energies are found to be in excellent agreement with the predictions of the aforementioned tight-binding calculations.

Item Type:	Article
Additional Information:	Published in Physical Review B, 76, 075209. © 2007 The American Physical Society.
Divisions:	Faculty of Engineering and Physical Sciences > Electronic Engineering > Advanced Technology Institute > Photonics Faculty of Engineering and Physical Sciences > Physics
Depositing User:	Mr Adam Field
Date Deposited:	27 May 2010 14:44
Last Modified:	23 Sep 2013 18:34
URI:	http://epubs.surrey.ac.uk/id/eprint/1742

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