Interfacial Molecular Engineering of Rare Earth‐Doped Nanocrystals: Basic Principles, Construction Strategies, and Advanced Applications

Abstract Interfacial molecular engineering of rare earth‐doped nanocrystals (RE NCs) by incorporating surface organic emitters is receiving widespread attention in the area of functional nanomaterials. The resulting organic–inorganic nanoconjugates are able to integrate individual strengths and show exciting optical/electrical/magnetic functionalities. However, there is a shortage of systematic reviews reporting the most recent progress of interfacial molecular engineering of RE NCs. Thereby, this review presents a comprehensive and timely perspective on recent advances in interfacial molecular engineering of RE NCs. The crucial theoretical knowledge is first summarized, ranging from the luminescence mechanism of organic molecules/RE NCs to the energy transfer mechanisms at the organic–inorganic interface. Construction protocols for coupling organic molecules and RE NCs are then discussed, including chemical coordination and physical adsorption pathways. In particular, beyond traditional bio‐imaging/therapy, advanced applications of RE NCs enabled by interface molecular engineering are outlined, not limited to photoexcited 3D printing, light‐induced photochromism/deformation, individual micro‐modification, and dynamic procedure regulation. Finally, challenges and perspectives are presented to accelerate future progress and provide research guidance for the interfacial molecular engineering of RE NCs. This review provides a deeper and broader understanding of the interfacial molecular engineering of RE NC and pushes this technology closer to practical applications.