Resistive-switching and memory in halide perovskite nanoparticles through a corona-poling approach: Necessity of type-I core-shell structures

Abstract

We show a resistive-switching and associated memory phenomenon in core-shell nanostructures of halide perovskites, namely, CsPbCl3 in the core and Cs4PbCl6 as a shell layer. We have employed the corona poling technique to approach a carrier-tunneling process as a non-contact and localized mode of measurement while achieving the switching phenomenon; such measurements with a scanning tunneling microscope tip forbade filament-formation, which commonly yields a low-resistive state during a resistive-switching. Interestingly, nanoparticles of core-shell components, such as CsPbCl3 and Cs4PbCl6, did not result in resistive-switching even in wider experimental conditions. Scanning tunneling spectroscopy of CsPbCl3 and Cs4PbCl6 nanoparticles and of core-shell nanostructures evidenced a type-I band-alignment at the core-to-shell interface. We have discussed the occurrence of resistive-switching, which results in a memory phenomenon as well in terms of charge-confinements in the type-I energy architecture of core-shell nanoparticles. The results thereby substantiate the necessity of such a type-I band-alignment in yielding a resistive-switching without filament formation.