Morphology transformation of Ge2Sb2Te5 films induced by ultrashort laser pulses

Surface modification of phase-change materials using femtosecond laser irradiation offers significant potential for diverse applications due to the broad tunability of the material’s physical properties. In this study, atomic force microscopy was employed to investigate the surface morphology of Ge2Sb2Te5 thin films modified by femtosecond laser pulses (wavelength: 1030 nm). The obtained topographic maps were analyzed using fluctuation analysis and average mutual information methods, enabling the evaluation of correlation characteristics and the degree of surface ordering. The results demonstrate that as the crystallinity of the thin-film samples increases, both the correlation length and the scaling exponent exhibit a corresponding rise.