Separation of vibrational and static disorder in amorphous In-Se films by EXAFS

Adrianna W. Jabłońska ,  Andrzej Burian 

University of Silesia, Department of Biophysics and Molecular Physics, Uniwersytecka 4, Katowice 40-007, Poland

Abstract

Configurational disorder in amorphous materials is due to thermal vibration of atoms and their static displacements from equilibrium positions. These two components can be separated by means of two EXAFS experiments performed at room and low temperatures. In the present work semiconducting indium selenide amorphous films with Se content at 50, 60 and 66 at. % has been studied. Such a separation has fundamental importance for understanding of electronic and optical properties of amorphous semiconductors. The BM29 and BM32 beam lines at ESRF (Grenoble) were used to record the EXAFS spectra at room temperature and at 20K at the In and Se K-edge. The generalized Debye-Waller factors at both absorption edges for all investigated samples were derived from the EXAFS oscillations using standard processing procedures and the Marquard-Levenberg least squares method. At 20K the thermal vibrations are practically frozen out and the Debye-Waller factor is related only to static disorder, which is a source of amorphous nature. The correlations thermal-static disorder as a function of the chemical composition is disonssed.

Presentation: poster at E-MRS Fall Meeting 2003, Symposium B, by Adrianna W. Jabłońska
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-05-09 14:57
Revised:   2009-06-08 12:55
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