Regioselective on-surface crystallization of one-dimensional organic barcode-like heterostructures of MOFs with fluorescent stripe patterns.

Heterostructures, integrating different semiconducting materials in a single structure, are key components for various modern electrical and optoelectronic devices. However, it is difficult to maintain the sequential epitaxial nucleation due to the passivation of crystal seeds, thus resulting in limited spatial segments in heterostructures. Here, we report an interface-recognition assembly strategy assisted by Plateau-Rayleigh instability (PRI) to spontaneously form one-dimensional (1D) heterostructures featuring abundant fluorescent stripe patterns. Guided by 1D metal-organic frameworks (MOFs) templates with exposed electron-donating sites, the de-wetting process promotes the effective regioselective crystallization of solute molecules with electron-withdrawing feature on template surface, thus forming 1D barcode-like heterostructures. The spatial locations and number of the stripes are effectively controlled by PRI and template parameters, while their emission colors are primarily governed by the charge-transfer (CT) interactions between solutes. On this basis, we have achieved full-color and heterogeneous stripe patterns by tuning the CT strengths and controlling the stripe nucleation sequences, thus creating abundant 1D barcode-like heterostructures. Through integrating the photoisomers into stripes, these heterostructures exhibit time-dependent graphical patterns and enable construction of 2D photonic barcodes. Our work offers a supramolecular approach for patterning of well-aligned organic heterostructures and rational design of optoelectronic devices that have potential in anti-counterfeiting applications.