High-efficiency tandem red organic light-emitting diodes adopting exciplex hosts

Abstract Deep-red organic light-emitting diodes (OLEDs) exhibit significant potential for applications in infrared medical treatment and infrared imaging. However, the OLED performance drops significantly with increasing emission wavelength due to the energy gap law. To overcome this challenge, an efficient interfacial exciplex host, NPB/TPBi, has been developed. Simulation results indicate that the interfacial exciplex host demonstrates superior performance, compared with the bulk exciplex host and single host. To further boost the performance of red OLEDs, the interfacial exciplex host was incorporated into tandem devices, achieving an external quantum efficiency of up to 27.3%. This work offers important insights for the fabrication of efficient red OLEDs.