Thermal relaxation processes in amorphous As-Se films

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Abstract
The influence of heat treatment on as‐deposited and darkened films of amorphous As7Se3 has been studied through its effects on the optical properties. The transmission of as‐deposited films increases with heat treatment and reaches a certain value Ts. This value depends on the heat‐treatment temperature, suggesting the structural relaxation of as‐deposited films upon heat treatment. The results of kinetics studies indicated that this relaxation consists of two first‐order rate processes; one is a rapid process at the initial 5‐min heat treatment and is considered to be due to the disapperance of structural defects in the as‐deposited films. The second is a slow process following the initial rapid process and is associated with the relaxation of the glass structure at high temperature. In the darkened film, the transmission increases with heat treatment and the value of Ts is independent of the heat‐treatment temperature. This process consists of only one first‐order rate process and was considered to be due to the ’’dissociative diffusion’’ of arsenic atoms.