Stepwise Solution-Interfacial Nanoarchitectonics for Assembled Film with Full-Color and White-Light Circularly Polarized Luminescence

The fabrication of chiral thin films with tunable circularlypolarizedluminescence (CPL) colors is important in developing chiroptical materialsbut remains challenging due to the lack of assembly-initiated chiralfilm formation methodology. Here, by adopting a combined solutionaggregation and interfacial assembly strategy, we report the fabricationof chiral film materials with full-color and white-light CPL. A biquinolineglutamic acid ester (abbreviated as BQGE) shows a typical aggregation-inducedemission property with blue CPL after solution aggregation. Subsequentinterfacial assembly of these solution aggregates on a solid substrateleads to the formation of a CPL active film consisting of nanobeltstructures. Since the BQGE molecule has a coordination site, the CPLemission of an individual BQGE film can be extended from blue to greenemission upon coordination with a zinc ion, accompanied by morphologytransition from nanobelts to nanofibers. Further extension to red-colorCPL is successfully achieved by coassembly with an achiral acceptordye. Interestingly, the proper combination of coordination ratio andacceptor loading ratio provides bright white-light CPL emission fromthe BQGE/Zn2+/PDA triad composite film. This work providesa new approach to fabricating chiroptical film materials with controlledmicroscopic morphology and tunable CPL properties.