Enhanced performance of inverted CsPbBr3 nanocrystal LEDs via Zn(II) doping

Perovskite lighting-emitting diodes (PeLEDs) with inverted structure have been considered as promising display technology due to their suitable driving schemes with n-type thin-film transistors. However, the defects and imbalanced charge carriers in the CsPbBr 3 nanocrystal (NC) PeLED are key hurdles, limiting the performance. Herein, we have successfully doped Zn 2+ ions into CsPbBr 3 NCs by ligand-assisted reprecipitation method, exhibiting an 85% enhancement of the photoluminescence quantum yield (PLQY). In addition, the optimized energy level alignment via Zn doping facilitates the carrier balance in the devices, improving the efficiencies. The obtained CsPbBr 3 :Zn-based PeLED reaches a high luminance of 3124 cd/m 2 and a maximum external quantum efficiency (EQE) of 0.85%, which are superior to those of CsPbBr 3 -based PeLED (luminance = 564 cd/m 2 , EQE = 0.09%). The results demonstrate that Zn doping significantly enhances the performance of PeLED, which increases the potential of these inverted PeLEDs connected with n-type TFTs towards practical applications.