Improved electronic uniformity and nanoscale homogeneity in template-grown CsPbBr₃ nanorods

One-dimensional metal halide perovskites are among the most promising candidate materials for optoelectronic devices. However, the heterogeneity and fast degradation of perovskite nanowires (NWs) and nanorods (NRs) synthesized using conventional approaches impose a bottleneck for their optoelectronic applications. Recently, all-inorganic perovskite CsPbBr₃ NRs with tailored dimensions, crafted using an amphiphilic bottlebrush-like block copolymer (BBCP) as nanoreactors, have demonstrated enhanced stabilities. Herein, we report the electronic investigation into these template-grown CsPbBr₃ NRs using dielectric force microscopy (DFM), a contactless, nondestructive imaging technique. All freshly prepared CsPbBr₃ NRs exhibited ambipolar behaviors for up to two months after sample synthesis. A transition from ambipolar to p-type behaviors occurred after two months, and nearly all NRs completed the transition within two weeks. Moreover, template-grown CsPbBr₃ NRs displayed better nanoscale electronic homogeneity compared to their conventional counterparts. The improved electronic uniformity and nanoscale homogeneity place the template-grown CsPbBr₃ NRs in a unique advantageous position for optoelectronic applications.