Switching and memory effects in partly crystallized amorphous Ge2Sb2Te5 films in a current controlled mode

Abstract Switching and memory effects in as-deposited amorphous Ge2Sb2Te5 films with a considerable concentration of crystalline nuclei have been investigated. Variation of the phase composition of the sample has been confirmed by Raman spectroscopy data. The influence of nuclei on parameters of the current voltage characteristic has been studied. Significant variation of initial resistance and threshold voltage due to a different nuclei configuration has been observed. In some cases the current voltage characteristic was monotonous i.e. the intrinsic S-shape of the current–voltage characteristic disappeared and memory recording occurred without prior switching. The measurements were made in a current controlled mode which allowed conducting a thorough investigation of switching and current filament formation.