Local atomic order and optical properties in amorphous and laser-crystallized GeTe

TitleLocal atomic order and optical properties in amorphous and laser-crystallized GeTe
Publication TypePalaiseau Article
Short TitleLocal atomic order and optical properties in amorphous and laser-crystallized GeTe
Acknowledgements

Nanoquanta, MC Training Site

DOI10.1016/j.crhy.2008.09.002
Wełnic, W, Wuttig, M, Botti, S, Reining, L
Year of Publication2009
JournalC.R. Physique
Volume10
URLhttp://www.em-consulte.com/article/226502
KeywordsElectronic structure calculations, paper, Phase change materials, RPA
Abstract

In this work we study the role of short-range order changes upon amorphization on the optical properties of GeTe – a prototype phase change material employed for optical data storage. It is found that the profound change in the absorption is due to changes in the matrix elements of the optical transitions. The importance of the local distortions in the crystalline phase for the optical absorption are revealed as well. Modifying the degree of the distortions has a significant impact on the optical properties of the crystalline state and should therefore become a promising instrument to improve material properties for storage applications.

Furthermore we study the effect of electron–electron and electron–hole interactions on the optical properties. This is achieved by evaluating many-body effects in the crystalline phase through a GW correction of eigenvalues and the solution of the Bethe–Salpeter equation.

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