Synergistic Effect of Zn2+ Cation Doping and Te2− Anion Passivation on CsPbBrxI3‐x Nanocrystals for Efficient Perovskite Light‐Emitting Diodes

The challenges of instability and surface defects in CsPbBrxI3‐x nanocrystals (NCs) pose significant limitations on their potential application in high‐performance pure‐red perovskite light‐emitting diodes (PeLEDs). Herein, a synergistic strategy of divalent cation (Zn2+) doping and anion (Te2−) passivation is proposed to solve these issues. Density functional theory analysis reveals that the synergistic effect can not only reduce the formation energy of CsPbBrxI3‐x NCs but also increase theiodide vacancy defect formation energy of CsPbBrxI3‐x NCs. Consequently, the optimized Zn2+/Te2− co‐modified CsPbBrxI3‐x NCs exhibit significantly enhanced stability with a near‐unity photoluminescence efficiency. Pure‐red PeLEDs based on these CsPbBrxI3‐x NCs possess outstanding spectral stability with a maximum external quantum efficiency and luminance of 16.1% and 1397.2 cd m−2, respectively. This synergistic strategy provides a new approach for enhancing the performance of mixed halide perovskite NCs and the corresponding optoelectronic devices. Mixed halide CsPbBrxI3‐x NCs are modified by a synergistic strategy of Zn2+ ion doping and Te2− ion passivation. The Zn2+/Te2− co‐modified CsPbBrxI3‐x NCs exhibit excellent stability against light radiation, high temperatures, and humidity. The pure‐red PeLEDs based on these NCs exhibit exceptional spectral stability with a peak external quantum efficiency of 16%.