Group‐VA Doped ZnO Injection Layer for Bright and Efficient Perovskite Light‐Emitting Diodes

Abstract

Heteroatom doping of the ZnO electron injection layer (EIL) is widely applied to the fabrication of high‐performance quantum‐dot and perovskite light‐emitting diodes (PeLEDs), while group‐VA atomic dopant is rarely studied. Here, VA bismuth (Bi) with strong metallicity is screened as a substitution dopant to regulate the colloid size, surface terminal, and defect density of the ZnO precursor. The as‐fabricated Bi‐doped ZnO (ZnBiO) EIL shows enhanced conductivity, passivated trap states, more n‐type nature, and appropriate band alignment with FAPbI3 (FA: formamidinium), contributing to smooth injection paths with minimal transport losses. Promoted by inhibited hydroxyl terminations of ZnBiO, the FAPbI3 crystals grown into flat nanocylinder domains with higher crystallinity and area‐thickness ratio, leading to a champion PeLED efficiency of 22.3%, a high near‐infrared radiance of 684 W sr−1 m−2, and nearly an order of magnitude extended operational stability, which shows great promise of ZnBiO as the optimal EIL for various LED application scenarios beyond classical ZnMgO.