Crystalline architectures of C₈₄ with tunable morphology and linearly polarized red emission

Fullerene-based micro/nano-architectures (FMNAs) with remarkable photoluminescence (PL) emissions have attracted considerable interest as potential building blocks for optical and biolabeling applications, by virtue of their low toxicity and environmentally friendly nature. Nevertheless, the PL polarization properties of FMNAs have rarely been explored. Herein, we demonstrate the preparation of highly crystalline architectures of C₈₄, which exhibit polymorphism depending on the preparation conditions but possess similar hexagonal close-packed (hcp) structures. The PL data demonstrate that the as-prepared carambola-like hexagonal microprisms (c-HPs) show enhanced red emission compared to regular hexagonal microprisms (r-HPs). More importantly, the linear polarization of the PL emission is verified and estimated through single-prism spectroscopy, which changes from 0.42 (r-HP) to 0.58 (c-HP), comparable to those of traditional rod-like semiconductors. Thus, we demonstrate a significant correlation between the morphology and emission characteristics of C₈₄-based microprisms, highlighting the possibility of controlling the photophysical properties of FMNAs by finely tailoring their external morphologies. This study expands the range of carbon materials with linearly polarized emissions and offers potential for use in polarization-based micro-scale sensors or detectors.