Overcoming efficiency trade-offs in organic devices: A new pathway to electroluminescence–photovoltaic conversion coexistence

Achieving both high electroluminescence (EL) efficiency and power conversion efficiency (PCE) in a single organic device has long been considered challenging, as these processes are fundamentally opposite. In this study, we present a novel strategy for material selection and device design to overcome this limitation and realise the unprecedented coexistence of high EL and photovoltaic (PV) efficiencies. By precisely controlling charge-transfer states at donor/acceptor interfaces, we successfully achieved full-spectrum visible EL without triplet–triplet annihilation upconversion while maintaining efficient charge generation essential for PV operation. The optimised multifunctional devices exhibited emission colours ranging from blue to red, as well as white, with the green- and orange-light-emitting devices achieving an external quantum efficiency of EL exceeding 8.5% and a PCE of about 0.5%. These findings not only overcome conventional efficiency trade-offs in organic devices but also open new avenues for innovative applications, including self-powered displays and lighting, potentially transforming optoelectronic technologies.