Tetraphenylethylene derivative capped CH₃NH₃PbBr₃ nanocrystals: AIE-activated assembly into superstructures

The surfaces of semiconductor nanocrystals have been known to be a very important factor in determining their optical properties. The introduction of functionalized ligands can further enhance the interactions between nanocrystals, which is beneficial for the assembly of nanocrystals. In a previous report, we developed a ligand-assisted reprecipitation method to fabricate organometal halide perovskite nanocrystals capped with octylamine and oleic acid. Here, a TPE derivative 3-(4-(1,2,2-triphenylvinyl)phenoxy)propan-1-amine, which shows a typical aggregation induced emission feature, is applied to replace octylamine to fabricate CH₃NH₃PbBr₃ nanocrystals. The obtained CH₃NH₃PbBr₃ nanocrystals were nanocubes (average diameter ∼ 11.1 nm) and are likely to assemble into ordered superstructures. By adjusting the chain length of the TPE derivative, we found that the assembly of the CH₃NH₃PbBr₃ nanocrystals was correlated with the interactions between the TPE groups. This provides a new platform to investigate the ligand effects in nanocrystal solids and may potentially achieve enhanced optical and electrical properties.