Polylactic Acid‐Based Luminescent Composites: Preparation Strategies, Performance Regulation, and Application Prospects

Luminescent materials are vital for diverse technological applications, such as light‐emitting diodes, medical diagnostics, and bio‐imaging, owing to their ability to convert energy into visible light. Traditional rare‐earth complexes face significant limitations, including resource scarcity, environmental toxicity, and aggregation‐caused quenching, that compromise efficiency in solid‐state devices, prompting a shift toward sustainable bio‐based polymers, with polylactic acid (PLA) emerging as a key candidate. This review addresses the urgent need for high‐performance, eco‐friendly alternatives by developing PLA‐based luminescent composites, which overcome previous challenges of toxicity, resource inefficiency, and quenching in conventional rare‐earth systems. Key outcomes demonstrate the successful integration of diverse dopants such as rare‐earth coordination complexes, boron compounds, inorganic phosphors, and perovskite derivatives into PLA matrices through physical doping and chemical bonding strategies, yielding enhanced optical properties including improved thermal stability, controlled room‐temperature phosphorescence, and resistance to quenching. These composites significantly advance photonic materials research by harmonizing superior functionalities like tunable emissions and chiral luminescence with the demands of environmental sustainability and resource efficiency. The incorporation of PLA's unique structural features, such as its inherent chirality and crystallinity, enables unprecedented control over molecular organization and excited‐state dynamics for applications in anti‐counterfeiting and sensors. Future research should focus on optimizing dopant‐polymer synergies to unlock potential in circularly polarized emission and expand the use of these composites in scalable green photonic technologies.