Bright Blue Light-Emitting Diodes Based on Well-Modified Carbon Dots by Designing Co-Host Systems to Balance Carriers’ Injection

摘要

Leveraging bright and stable carbon dots (CDs) for blue light-emitting diodes(LEDs) is a prospective but challenging topic. Aggregation-caused quenching(ACQ) of CDs and device engineering of CDs-LEDs are two issues. Here, blueCDs with quantum yield of 59.75 are synthesized. Hydrogen bonds increaserigidity and facilitate luminescence, while polymer chains increase spatialresistance and resist ACQ. Then, solution-processed blue CDs-LEDs areassembled by blending CDs into poly(N-vinylcarbazole) (PVK) aslight-emitting layer (EML). Furthermore, several other materials are alsoemployed as the second host to reduce injection barrier, facilitate carriers’transport, and balance carriers’ distribution. In particular, the blue CDs-LEDbased on the co-host system of PVK and4-1-4-bis(4-methylphenyl)aminophenylcyclohexyl-N-(3-methylphenyl)-N-(4-methylphenyl)benzenamine (TAPC) achieves a maximum brightness up to827.60 cd m~(?2). This work is a step forward for applying CDs in LEDs.