Bright Blue Light Emission of Ni2+ Ion-Doped CsPbCl x Br3- x Perovskite Quantum Dots Enabling Efficient Light-Emitting Devices

Gencai Pan; Xue Bai; Wen Xu; Xu Chen; Yue Zhai; Jinyang Zhu; He Shao; Nan Ding; Lin Xu; Biao Dong; Yanli Mao; Hongwei Song

doi:10.1021/acsami.0c01074

Bright Blue Light Emission of Ni²⁺ Ion-Doped CsPbCl _x Br_{3- x} Perovskite Quantum Dots Enabling Efficient Light-Emitting Devices

ACS Appl Mater Interfaces. 2020 Mar 25;12(12):14195-14202. doi: 10.1021/acsami.0c01074. Epub 2020 Mar 11.

Authors

Gencai Pan^{1

2}, Xue Bai¹, Wen Xu¹, Xu Chen³, Yue Zhai¹, Jinyang Zhu¹, He Shao¹, Nan Ding¹, Lin Xu¹, Biao Dong¹, Yanli Mao², Hongwei Song¹

Affiliations

¹ State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China.
² School of Physics and Electronics, Henan University, No. 1, Jinming Street, Kaifeng 475004, P. R. China.
³ School of Physics and Microelectronics, Zhengzhou University, 100 Kexue Avenue, Zhengzhou 450015, P. R. China.

PMID: 32093480
DOI: 10.1021/acsami.0c01074

Abstract

In recent years, significant advances have been achieved in the red and green perovskite quantum dot (PQD)-based light-emitting diodes (LEDs). However, the performances of the blue perovskite LEDs are still seriously lagging behind that of the green and red counterparts. Herein, we successfully developed Ni²⁺ ion-doped CsPbCl_xBr_3-x PQDs through the room-temperature supersaturated recrystallization synthetic approach. We simultaneously realized the doping of various concentrations of Ni²⁺ cations and modulated the Cl/Br element ratios by introducing different amounts of NiCl₂ solution in the reaction medium. Using the synthetic method, not only the emission wavelength from 508 to 432 nm of Ni²⁺ ion-doped CsPbCl_xBr_3-x QDs was facially adjusted, but also the photoluminescence quantum yield (PLQY) of PQDs was greatly improved due to efficient removal of the defects of the PQDs. Thus, the blue emission at 470 nm with PLQY of 89% was achieved in 2.5% Ni²⁺ ion-doped CsPbCl_0.99Br_2.01 QDs, which increased nearly three times over that of undoped CsPbClBr₂ QDs and was the highest for the CsPbX₃ PQDs with blue emission, fulfilling the National Television System Committee standards. Benefiting from the highly luminous Ni²⁺ ion-doped PQDs, the blue-emitting LED at 470 nm was obtained, exhibiting an external quantum efficiency of 2.4% and a maximum luminance of 612 cd/m², which surpassed the best performance reported previously for the corresponding blue-emitting PQD-based LED.

Keywords: Ni2+ ion doping; anion exchange; blue emission; perovskite QD-LEDs; perovskite quantum dots.