Direct-to-indirect band gap crossover for the BexZn1-xTe alloy

Citation
O. Maksimov et Mc. Tamargo, Direct-to-indirect band gap crossover for the BexZn1-xTe alloy, APPL PHYS L, 79(6), 2001, pp. 782-784
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
79
Issue
6
Year of publication
2001
Pages
782 - 784
Database
ISI
SICI code
0003-6951(20010806)79:6<782:DBGCFT>2.0.ZU;2-U
Abstract
We have investigated the growth and optical properties of a set of BexZn1-x Te epitaxial layers having different composition, with x ranging from 0-0.7 . Comparison of the reflectivity and the photoluminescence spectra allowed us to locate the direct-to-indirect band gap crossover for this alloy at x approximate to0.28. The Gamma --> Gamma direct band gap exhibits a linear d ependence on composition over the entire compositional range and can be fit ted to the equation E-Gamma (g)(x)=2.26*(1- x)+4.1*x. It increases linearly with BeTe content at a rate of 18 meV for a change of 1% in BeTe content. The Gamma -->X indirect band gap for BexZn1-xTe can be fitted to the equati on E-X (g)(x)=3.05*(1-x)+2.8*x-0.5*x*(1- x), suggesting that the energy of the indirect Gamma -->X transition for ZnTe is about 3.05 eV. (C) 2001 Amer ican Institute of Physics.