Optical properties of (GeTe, Sb2Te3) pseudobinary thin films studied with spectroscopic ellipsometry

Jun Woo Park, Seoung Ho Baek, Tae Dong Kang, Hosun Lee, Youn Seon Kang, Tae Yon Lee, Dong Seok Suh, Ki Joon Kim, Cheol Kyu Kim, Yoon Ho Khang, Juarez L.F. Da Silva, Su Huai Wei

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

Abstract

The authors measure the dielectric functions of (GeTe, Sb 2Te3) pseudobinary thin films by using spectroscopic ellipsometry. By using standard critical point model, they obtained the optical transition (critical point) energies of the amorphous (crystalline) thin films. The optical (indirect band) gap energies of the amorphous (crystalline) phase are estimated from the linear extrapolation of the absorption coefficients. The band structure calculations show that GeTe, Ge2 Sb2 Te5, and Ge1 Sb2 Te4 have indirect gap whereas Ge1 Sb4 Te7 and Sb2Te3 have direct gap. The measured indirect band gap energies match well with electronic band structure calculations.

Original languageEnglish
Article number021914
JournalApplied Physics Letters
Volume93
Issue number2
DOIs
StatePublished - 14 Jul 2008

Bibliographical note

Funding Information:
The work at KHU was supported by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (R01-2007-000-20142-0). The work at NREL is supported by the U.S. Department of Energy, under Contract No. DE-AC3699GO10337. J.W.P. was supported in part by a 2007 Graduate Student Scholarship from Kyung Hee University.

Fingerprint

Dive into the research topics of 'Optical properties of (GeTe, Sb2Te3) pseudobinary thin films studied with spectroscopic ellipsometry'. Together they form a unique fingerprint.

Cite this