Bright and Stable Top‐Emitting Quantum‐Dot Light‐Emitting Diode Enabled by a Self‐Assembled Monolayer

ABSTRACT Although high‐efficiency top‐emitting quantum‐dot light‐emitting diodes (TE‐QLEDs) can be realized through optical optimization, their brightness and operational lifetime remain stringently constrained. Here, we demonstrate a TE‐QLED featuring a [2‐(3‐bromo‐6‐phenyl‐9H‐carbazol‐9‐yl)ethyl]phosphonic acid (PhBr‐2PACz) self‐assembled monolayer (SAM) strategically inserted between the hole injection layer (HIL) and hole transport layer (HTL). This SAM serves a dual function of reducing hole injection barrier and suppressing leakage current, thereby leading to significantly improved charge balance within the device. Through systematic optimization of light out‐coupling efficiency and charge injection balance, we successfully achieved TE‐QLEDs with a high external quantum efficiency (EQE) of 36.53%, an exceptional peak brightness of 1 583 000 cd/m 2 , and an impressive T 95 lifetime of 28 612 h at an initial brightness of 1000 cd/m 2 . To the best of our knowledge, these brightness and lifetime values are the highest ever reported for TE‐QLEDs on glass substrates without additional heat dissipation. We believe that the demonstrated high‐efficiency TE‐QLEDs, with exceptional brightness and stability, are expected to significantly advance the commercialization of QLEDs in display and lighting applications.