Interface-directed charge regulation enables efficient perovskite/organic hybrid tandem LEDs

Near infrared (NIR) light-emitting devices hold significant promise for applications in night vision, telecommunications, and biomedical imaging. Hybrid tandem light-emitting diodes (LEDs) that combine quantum-dot (QD)-based and organic emissive subunits represent a compelling strategy to surpass an external quantum efficiency (EQE) of 30%. However, in series-connected architectures, the intrinsic mismatch in charge-transport properties and distinct efficiency roll-off characteristics between the two emissive units hinder ideal efficiency summation and limit overall device performance under identical current injection. Here, we report a high-performance hybrid NIR tandem LED in which this imbalance is mitigated by selectively enhancing carrier injection and transport in the performance-limiting QD-based emissive unit. Through molecular engineering of the electron-transporting layer and rational design of the charge-generation interface, the electrical characteristics of the QD unit is precisely tailored to match that of the high-efficiency organic NIR emitter. As a result, the hybrid tandem device achieves a near-ideal voltage addition and markedly improved electroluminescence, delivering a peak external quantum efficiency of 35% with stable emission at 780 nm. This work establishes a general design principle for overcoming current-driving imbalance in heterogeneous tandem architectures and paves the way toward high-performance NIR light sources.