High‐Performance Near‐Infrared Organic Light‐Emitting Diodes Based on Grating‐Structured Hole Transport Layer

Near‐infrared (NIR) organic light‐emitting diodes (OLEDs) based on acceptor‐donor‐acceptor (A‐D‐A)‐type molecules are attractive for applications in biological imaging, optical communication, and night vision. However, their performance is often limited by low radiative efficiency arising from unfavorable exciton recombination zones and poor light outcoupling. Here, we demonstrate high‐performance NIR OLEDs by incorporating a one‐dimensional Bragg grating into a thermally cross‐linkable hole‐transporting layer (PF8Cz‐X) via microtransfer molding. This interlayer introduces hole traps that confine the exciton recombination zone to the vicinity of the anode, substantially enhancing the Purcell factor and boosting the effective radiative quantum efficiency. Simultaneously, the imprinted grating modifies the optical mode distribution, scattering surface plasmon polariton modes into extractable light. The optimized devices exhibit an emission peak at 880 nm, a maximum external quantum efficiency of 1.55%, and a peak radiant exitance of 74.67 mW cm −2 , representing one of the highest‐performing solution‐processed NIR OLEDs beyond 800 nm. This work establishes a synergistic electrical and optical engineering strategy to overcome efficiency limitations in NIR OLEDs.