Quenching-Resistant Polymer Carbon Dot Preserving Emission Color Consistency in Solid-State

Solid-state luminescent carbon dot without dispersion matrices is studied to overcome aggregation-caused quenching, but it usually shows spectral shift between solution- and solid-state accompanying a dramatic decrease of fluorescence intensity, which hinders a real application. Herein, polymer carbon dot (PCD) showing solid-state luminescence without red-shift is synthesized by low-temperature reaction. The PCD solution and solid have the same emission peaks at 434 nm and similar absolute quantum yields of 68.2% and 62.7%, respectively, which is uncommon feature compared to other carbon dots. The mechanism for solid-state luminescence and emission color consistency is investigated by structural analysis of the PCD compared to carbon dot that shows red-shift in solid-state. The PCD is utilized into light-emitting diode application as a phosphor, and little color change in emission without significant decrease in luminous efficacy is achieved even with high loading fraction (50 wt%), opening the possibility of real application in solid-state lighting.