Unraveling the Electronic Heterogeneity and Inhomogeneity in Individual Perovskite CsPbBr3 Nanowires

Perovskite nanowires (NWs) have attracted significant attention due to their promise in optoelectronic applications. All-inorganic perovskite CsPbBr3 NWs with a well-defined morphology were synthesized using a hot-injection approach. Subsequently, the electronic properties of individual CsPbBr3 NWs spun onto SiO2/Si substrates were scrutinized by contactless dielectric force microscopy (DFM). Ambipolar, n-type, and p-type responses were identified for different NWs, revealing the electronic heterogeneities of CsPbBr3 NWs. Moreover, longitudinal electronic inhomogeneities were uncovered by the distinct DFM responses of different segments along some NWs whose diameters were 10-20 nm. In addition, DFM experiments unveiled transverse electronic inhomogeneities perpendicular to the length direction in some NWs whose diameters were 30-40 nm. This work demonstrates that the DFM technique is a powerful tool to probe the electronic heterogeneity and inhomogeneity in perovskite NWs, which may have implications for the performance of materials and devices built upon them. In principle, our approach reported here could be extended to study the electronic properties of other one-dimensional metal halide perovskites.