Precursor-dependent photoluminescence diversity in carbonized polymer dots: the luminophores and crosslinking

Carbonized polymer dots (CPDs) represent a prominent subclass of luminescent carbon dots (CDs), distinguished by their unique core-shell nanostructures and exceptional optical performance. Over the past decade, CPDs have experienced significant growth, as they provide a promising approach to fabricate efficient luminophores at the nanoscale through simple and environmentally friendly methods. Various precursors, including small molecules, polymers and biomass, have proved to be effective for the synthesis of CPDs, leading to a diversity of photoluminescence (PL) properties, albeit with ongoing debates regarding the origins of PL. Herein, the precursor-dependent luminophores and crosslinking reactions are expounded in several representative CPDs to reveal the enhanced PL emissive behaviors that differ from traditional small molecules or polymers. We emphasize the synergistic contributions of molecular-state fluorophores and crosslink-enhanced emission effect in highly luminous CPDs. Additionally, we propose future development trends for CD materials to foster open discussion and guidance.