Raman Spectroscopy of Chalcogenide Thin Films Prepared by PLD

ERAZU, M.; ROCCA, J.; FONTANA, M.; MARIA ANDREA UREÑA; ARCONDO, B.; PRADEL, A.

Buenos Aires, Argentina

Simposio; 15 International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials (ISMANAM 2008); 2008

Abstract: Chalcogenide glasses have many technological applications as a result of their particular opticaland electrical properties. Ge-Se and Ag-Ge-Se systems were recently studied and tested as new materialsfor building non-volatile memories [1]. Following these ideas, thin films of Ge-Se and Ag-Ge-Se weredeposited using PLD (Pulsed Laser Deposition). Ag was sputtered over binary films (for a compositionbetween 0.05 and 0.25 Ag at. fraction) and photodiffused afterwards. Thus, three kinds of samples wereanalyzed by means of Raman spectroscopy, in order to provide information on the short and medium rangeorder: PLD binary films before Ag doping, after Ag doping and PLD ternary films.Before Ag doping, binary films exhibited Ge-Se corner-sharing tetrahedra modes at 190 cm-1, low scatteringfrom edge sharing tetrahedra at 210 cm-1, and Se chains at 260 cm-1 (stretching mode). However, after thediffusion process was complete, we observed an intensity reduction of bands centered at 210 cm-1 and 260cm-1. The spectra of the photodiffused films were similar to those of films deposited using a ternary target.Relaxation effects in binary glasses were also analyzed. Results were compared with those of other authors.