Temperature dependent optical constants of amorphous Ge2Sb2Te5 thin films

Vinod, EM and Naik, Ramakanta and Faiyas, APA and Ganesan, R and Sangunni, KS (2010) Temperature dependent optical constants of amorphous Ge2Sb2Te5 thin films. In: Journal of Non-Crystalline Solids, 356 (41-42). pp. 2172-2174.

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Abstract

This study focuses on the temperature dependent optical band gap changes in the amorphous Ge2Sb2Te5 (GST) films. The behavior of the amorphous GST thin films at low temperatures has been studied. The band gap increment of around 0.2 eV is observed at low temperature (4.2 K) compared to room temperature (300 K). The band gap changes associated with the temperature are completely reversible. The other optical parameters like Urbach energy and Tauc parameter (B-1/2) are studied for different temperatures and discussed. The observed changes in optical band gap (E-g) are fitting to Fan's one phonon approximation. Phonon energy ((h) over bar omega) corresponding to a frequency of 3.59 THz is derived from Fan's approximation, which is close to the reported value of 3.66 THz. (C) 2010 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Journal of Non-Crystalline Solids
Publisher:	Elsevier Science B.V.
Additional Information:	Copyright of this article belongs to Elsevier Science B.V.
Keywords:	Chalcogenides (ChG); Ge2Sb2Te5 (CST); Optical band gap; Urbach energy
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	18 Nov 2010 12:18
Last Modified:	18 Nov 2010 12:18
URI:	http://eprints.iisc.ac.in/id/eprint/33834

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