Structural relaxation and optical properties in amorphous Ge33As12Se55 films

Abstract Amorphous Ge 33 As 12 S 55 films prepared by ultra fast pulsed laser deposition (PLD) have been vacuum annealed over a range of different temperatures. Raman scattering measurements indicated that the features corresponding to Ge–Se and As–Se clusters increase in intensity with increasing annealing temperature ( T a ) up to their respective glass transition temperature, and then decrease with further increasing T a up to 300 °C. Optical property measurements showed that the refractive index deceases but the optical band gap increases with increasing T a , and both of them could be fitted by the exponential function. The corresponding characteristic time extracted was found not to obey Arrhenius behavior, which is consistent with the existence of a broken network cut by cross-linking bonds and different clusters in films.