A quinoxaline based N-heteroacene interfacial layer for efficient hole-injection in quantum dot light-emitting diodes.

A series of N-heterocyclic quinoxaline derivatives was successfully synthesized and applied as hole transport layers in quantum dot light-emitting diodes (QLEDs). By inducing sp(2) N-atoms into the quinoxaline backbone, the electron affinity of the obtained material was enhanced, and its optical properties and bandgap became tunable. Quinoxaline based N-heteroacenes show a narrow bandgap, high thermal stability, and aligned film morphology. The resulting N-heteroacene polymer based QLED exhibits superior performance to poly(9-vinylcarbazole) based QLED. This study presents a strategy towards the design of novel N-rich molecules for the fabrication of QLEDs with improved performance.