Optical characterization of rocksalt Pb1-xSnxTe alloys

✍ Scribed by Dantas, Nilton Souza ;Arwin, Hans ;Nzulu, Gabriel ;de Oliveira Rappl, Paulo Henrique ;da Silva, Antônio Ferreira ;Persson, Clas

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 365 KB
• Volume: 205
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200777747

✦ Synopsis

Abstract

The optical properties in terms of dielectric function ϵ (ħω) = ϵ~1~(ħω) + iϵ~2~(ħω) of rocksalt Pb~1–x~ Sn__~x~__ Te alloys (0 ≤ x ≤ 1) are investigated experimentally by spectroscopic ellipsometry and theoretically by first‐principles electronic band structure calculation. We find a strong optical response in the 0.5–2.0 eV region arising from optical absorption around the LW‐line of the Brillouin zone. The response peak of the imaginary part of the dielectric functions at E = 1.6–1.8 eV shifts towards lower energies for high Sn compositions as a consequence of narrower W‐point band‐gap E~g~(W) for the Sn‐rich alloys. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)