5‐3: <i>Distinguished Student Paper:</i> Highly Efficient and Bright Green Quantum‐Rod Light‐Emitting Diodes with Eliminated Charge Leakage

Quantum rods (QRs) have the potential to double the external quantum efficiency (EQE) of light‐emitting diodes (LEDs) compared to traditional spherical quantum dot (QD) LEDs. However, the EQE and brightness need to catch up to those of QD‐LEDs. One of the primary factors contributing to this issue is electron leakage and parasitic emission from the hole transport layer (HTL), diminishing the EQE and brightness by over 80%. In this study, we systematically analyzed charge transport behavior in QR‐LEDs and identified the pathways for electron leakage. We discovered two primary leakage paths enabling simultaneous electron‐hole recombination in the QRs and the HTL. The electroluminescence (EL) spectra indicate that the parasitic emission from the HTL is substantial, accounting for more than 50% of the signal compared to that of the QRs. We enhanced device performance by effectively suppressing electron leakage and improving hole injections in QR‐LEDs. As a result, QR‐LEDs achieved record‐breaking performance metrics: EQE of 19.4%, CE of 72 cd/A, and luminance of 320,000 cd/m 2 . These figures represent the highest recorded values for green QR‐LEDs.