Laterally Engineering Lanthanide‐MOFs Epitaxial Heterostructures for Spatially Resolved Planar 2D Photonic Barcoding

Metal‐organic frameworks (MOFs) heterostructures with domain‐controlled emissive colors have shown great potential for achieving high‐throughput sensing, anti‐counterfeit and information security. Here, a strategy based on steric‐hindrance effect is proposed to construct lateral lanthanide‐MOFs (Ln‐MOFs) epitaxial heterostructures, where the channel‐directed guest molecules are introduced to rebalance in‐plane and out‐of‐plane growth rates of the Ln‐MOFs microrods and eventually generate lateral MOF epitaxial heterostructures with controllable aspect ratios. A library of lateral Ln‐MOFs heterostructures are acquired through a stepwise epitaxial growth procedure, from which rational modulation of each domain with specific lanthanide doping species allows for definition of photonic barcodes in a two‐dimensional (2D) domain with remarkably enlarged encoding capacity. The results provide molecular‐level insight into the use of modulators in governing crystallite morphology for spatially assembling multifunctional heterostructures. Dimension‐tunable lateral Ln‐MOFs heterostructures were realized through spatial semi‐confinement induced steric hindrance. They exhibit domain‐controlled emissive colors and identifiable dimensional‐tunable lengths, offering unique opportunities to design integrated microstructures and smart devices toward advanced anti‐counterfeiting applications.