NANOMETER-SCALE MECHANISM OF REVERSIBLE PHOTO-STRUCTURAL CHANGES IN AMORPHOUS CHALCOGENIDES

摘要

The nanoscale mechanism of reversible photo-structural changes in amorphous chalcogenides is discussed, based on our recent experiments. Our in-situ EXAFS studies demonstrate an increased coordination number in the photo-excited state, suggesting the formation of dynamic interchain/layer bonds. The creation of new structural units is further established by Raman scattering. The decay of dynamic bonds had been studied by ESR which provides evidence for the formation of dangling bonds and three-fold coordinated defects. The effect of light polarisation is also considered.