Morphology analysis of nanostructure formation on CdBr2 and PbI2 crystal surfaces

Abstract

This study investigates the role of cationic and anionic subsystems in nanostructure formation on CdI2 crystals by analyzing CdBr2 and PbI2 surfaces using atomic force microscopy (AFM). After 1 d, CdBr2 developed triangular nanopores and island-shaped clusters. By day three, two nanostructure types emerged: small (200–600 nm) and large (�2lm) clusters. After seven days, nanopores increased, and nanowires formed via cluster aggregation, likely due to moisture-induced dissolution. CdBr2 exhibited faster nanostructure formation than CdI2 due to Br-’s higher reactivity. PbI2 surfaces remained smooth, showing atomic steps and quasi-periodic structures (�1.3lm period).