Photo-induced birefringence and surface ripples structures in As-S-Ag chalcogenide thin-films

• Autor(a) principal: Douaud, Alexandre
• Data de Publicação: 2019
• Outros Autores: Messaddeq, Sandra Helena, Messaddeq, Younès
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.jnoncrysol.2019.05.022; http://hdl.handle.net/11449/221302
• topic: Chalcogenide; Glass; Photo-induced birefringence; Silver; Thin-films

Photo-induced phenomena are investigated in new metastable Agx(As20S80)100-x chalcogenide thin-films prepared by the co-evaporation technique. Under irradiation using an Ar laser at 488 nm, periodic ripples structures formation are observed inside of the irradiated spot. With an increasing irradiation time or power density, a characteristic evolution of ripples is observed from a random structure to a series of generally aligned peaks-and-valleys periodic structures until a complete break-up of the film (laser dewetting). The scanning electron microscopy (SEM) of irradiated areas shows periodic ripples are aligned perpendicularly to the electric field vector of the incident light. Moreover, photo-induced birefringence (PIB) is observed during ripples formation. The kinetics of structural changes during the irradiation of the films is analysed using Raman spectroscopy. The molecular rearrangement from sulphur-cis toward sulphur-trans through irradiation is proposed to explain the experimentally observed PIB.