Photoinduced Elastic Changes in Amorphous As2S3 Films

Abstract
Viscous and elastic changes in amorphous As2S3 films induced by bandgap illumination have been investigated by means of the surface acoustic waves propagating in As2S3/LiNbO3 structures. It is found that the changes in the elastic constants are +20% and -4∼-12% in the irreversible and reversible processes respectively. In the irreversible process, the elasticity changes monotonically but the viscosity changes non-monotonically.