Carbon Dot Self‐Assembly: Bottom‐Up Fabrication, Morphological Evolution, Luminescence Regulation, and Advanced Applications

ABSTRACT Carbon dots (CDs) have garnered widespread interest in biosensing, optoelectronics, and biomedicine due to their exceptional fluorescence, biocompatibility, and low cost. While individual CDs exhibit tunable properties, their organization into higher‐order architectures via self‐assembly enables emergent collective functionalities that are inaccessible to discrete nanoparticles. This review presents a systematic overview of the design principles and recent advances in CD self‐assembly. We first summarize synthetic strategies and the morphological evolution of assemblies, spanning zero‐dimensional nanoparticles to three‐dimensional macroscopic materials. We then discuss how self‐assembly modulates photophysical properties, followed by an analysis of the underlying supramolecular mechanisms. Subsequently, representative applications enabled by these assemblies are highlighted. Finally, we outline key challenges related to scalability, stability, and the prediction of structure‐property relationships, and provide an outlook on leveraging self‐assembly to fully realize the potential of CDs for advanced functional materials.