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

doi:10.1063/1.2959818

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

Department of Physics

Research output: Contribution to journal › Article › peer-review

62 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 language	English
Article number	021914
Journal	Applied Physics Letters
Volume	93
Issue number	2
DOIs	https://doi.org/10.1063/1.2959818
State	Published - 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.

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10.1063/1.2959818

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@article{b017da87a67e46c0a6d193ce20446271,

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

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.",

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

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.",

year = "2008",

month = jul,

day = "14",

doi = "10.1063/1.2959818",

language = "English",

volume = "93",

journal = "Applied Physics Letters",

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publisher = "American Institute of Physics",

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T1 - Optical properties of (GeTe, Sb2Te3) pseudobinary thin films studied with spectroscopic ellipsometry

AU - Park, Jun Woo

AU - Baek, Seoung Ho

AU - Kang, Tae Dong

AU - Lee, Hosun

AU - Kang, Youn Seon

AU - Lee, Tae Yon

AU - Suh, Dong Seok

AU - Kim, Ki Joon

AU - Kim, Cheol Kyu

AU - Khang, Yoon Ho

AU - Da Silva, Juarez L.F.

AU - Wei, Su Huai

N1 - 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.

PY - 2008/7/14

Y1 - 2008/7/14

N2 - 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.

AB - 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.

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