Thermal-Responsive Self-Assembly of Organic Crystals With Asymmetric Architectures.

Abstract

The miniaturization and integration of electronic/photonic devices demand precise control over light at the micro-scale. However, achieving tailored optical anisotropy through intrinsic material design, rather than external components, remains a significant challenge. Herein, we report a general and programmable strategy for the growth of one-dimensional organic crystals with precisely tunable asymmetric architectures via a spatially defined temperature gradient. By leveraging the competitive, facet-dependent growth kinetics under a thermal bias, continuous and precise control over the structural asymmetry is achieved in single crystals, with a tunable morphological anisotropy ranging from 9% to 81%. The resulting asymmetric crystals exhibit a pronounced direction-dependent optical response, yielding a photoluminescence intensity contrast ratio as high as 113.3, which scales directly with the degree of structural asymmetry. This work establishes a material-based platform for applying direction-dependent photonic properties directly into crystal morphology, paving the way for advanced organic photonic materials with built-in anisotropy.