Synergistic regulation effect of magnesium and acetate ions on structural rigidity for synthesizing an efficient and robust CsPbI 3 perovskite toward red light-emitting devices.

The structure of CsPbI 3 nanocrystals (NCs) with excellent photoelectric properties easily collapses, which hinders their application in light-emitting diodes (LEDs). Herein, we accomplished the synthesis of efficient and stable CsPbI 3 NCs by regulating structural rigidity under the synergistic effect of Mg 2+ and AcO - ions. The introduced AcO - and Mg 2+ ions increase surface steric hindrance and defect formation energy, which enhances the structural rigidity of the perovskite. As a result, the CsPbI 3 NCs display an outstanding photoluminescence quantum yield of 95.7%, in conjunction with reduced defect state density, balanced carrier injection, and distinguished conductivity. Remarkably, the modified CsPbI 3 NCs exhibit excellent stability under ambient conditions for 180 days and can even survive when the temperature reaches 150 °C. Given their enhanced structural rigidity, LEDs made from these modified CsPbI 3 NCs exhibit a maximum luminance and an EQE of 3281 cd m -2 and 13.2%, respectively, which are significantly improved compared with those of unmodified CsPbI 3 NC LEDs.