Raman spectroscopy of chalcogenide thin films prepared by PLD

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

JOURNAL OF ALLOYS AND COMPOUNDS

Elsevier

Año: 2010 vol. 495 p. 642 - 645

0925-8388

Chalcogenide glasses have many technological applications as a result of their particular optical and electrical properties. Ge-Se and Ag-Ge-Se systems were recently studied and tested as new materials for building non-volatile memories. Following these ideas, thin films of Ge-Se and Ag-Ge-Se were deposited using PLD (Pulsed Laser Deposition). Ag was sputtered over binary films (for a composition between 0.05 and 0.25 Ag atomic fraction) and photodiffused afterwards. Thus, three kinds of samples were analyzed by means of Raman spectroscopy, in order to provide information on the short and medium range order: 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 scattering from edge sharing tetrahedra at 210 cm-1, and Se chains at 260 cm-1 (stretching mode). However, after the diffusion process was complete, we observed an intensity reduction of bands centered at 210 cm-1 and 260 cm-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.