Opto-electronics review, vol. 11(1), 2003, p. 19–25.
A microstructural mechanism of photoinduced structural transformations in amorphous As2Se3 thin films was studied by IR Fourier-transform spectroscopy in the range of 300–100 cm-1. It was shown that the stage of irreversible photostructural changes in the freshly-deposited films was connected with coordination of topological defects formation accompanied by homopolar chemical bonds switchings in heteropolar ones. By contrast, the reversible stage of photoinduced effects were caused by two different types of transformations – heteropolar bonds switching in homopolar ones, as well as heteropolar bridge bonds switching in short layer ones. Both processes were associated with the formation of anomalously coordinated topological defect pairs and atomic displacements at the medium-range ordering level.