Author(s): Tian, SY (Tian, Shuyu); Zhou, XF (Zhou, Xianfeng); Bi, CH (Bi, Chenghao); Sun, XJ (Sun, Xuejiao); Zhang, MQ (Zhang, Mengqi); Yang, SX (Yang, Shixu); Tian, JJ (Tian, Jianjun)

Source: ADVANCED OPTICAL MATERIALS Article Number: 2200751 DOI: 10.1002/adom.202200751 Early Access Date: JUN 2022

Abstract: Rapid performance degradation as temperature increases for metal halide perovskite nanocrystals (NCs) greatly restricts the practical application for lighting and display. This problem is even more grievous for the mixed-halide perovskite NCs because of severe ions migration. Here, a solid-reaction process in the N-2 atmosphere is devised, in which the red-emitting (631 nm wavelength) mixed halide CsPbBr1.5I1.5 NCs with a coating of SiO2 shell are achieved. Meanwhile, the Zn2+ and K+ ions are co-doped into the crystal lattice to enhance the radiative decay rate and decrease the trap density of the NCs. The photoluminescence quantum yield of the co-doped NCs reaches 64.5%, which is one of the highest values for the reported mixed-halide perovskite NCs obtained by the solid reaction. Importantly, the dopant of K+ enters into the interstitial position of the perovskite structure to increase the structural rigidity, which inhibits exciton-phonon interaction and elevates thermal activation energy, thus improving thermal quenching resistance to sustain high emission intensity at high temperature (>353 K). Furthermore, the red backlight emitting diode based on the NCs exhibits no decay in luminescence intensity after continuous operation for 700 h at 353 K, representing remarkable stability for the commercial application.

Accession Number: WOS:000809025300001

ISSN: 2195-1071

Full Text: https://onlinelibrary.wiley.com/doi/10.1002/adom.202200751