Peculiarities of silver photodissolution in (GeS4 ) (AsS3 )x-1 glassy films

Abstract

The kinetics of the photodissolution (PD) of Ag into glassy (GeS4 ) (AsS3 )x-1 films has been studied by monitoring the changes that occur in their optical transmission of weakly absorbed broadband light. It was shown that the kinetics profiles comprise two consecutive linear steps followed by a quasi – parabolic tail. The PD rate and the amount of adopted Ag on the first step were found (except of 4 GeS ) not to depend on glass composition. This result was ascribed to provide evidence for a preferential and direct interaction of Ag with free sulfur at the interface. The rate of PD on the second linear step exhibits a compositional maximum around 4 0.33 3 0.67 (GeS ) (AsS ) , being by two orders of magnitude higher than the rate for 4 GeS . The revealed compositional dependences are qualitatively attributed to the fact that only some, very specific glassy compositions being Ag photodoped yield a homogeneous material.