Chlorine Vacancy Passivation in Mixed-Halide Perovskite Quantum Dots by Organic Pseudohalides Enables Efficient Rec. 2020 Blue Light-Emitting Diodes
Type
ArticleAuthors
Zheng, XiaopengYuan, Shuai
Liu, Jiakai

Yin, Jun

Yuan, Fanglong
Shen, Wan-Shan
Yao, Kexin
Wei, Mingyang
Zhou, Chun
Song, Kepeng
Zhang, Bin-Bin
Lin, Yuanbao
Hedhili, Mohamed N.

Wehbe, Nimer
Han, Yu

Sun, Hong-Tao
Lu, Zheng-Hong
Anthopoulos, Thomas D.

Mohammed, Omar F.

Sargent, Edward H.
Liao, Liang-Sheng
Bakr, Osman

KAUST Department
Advanced Membranes and Porous Materials Research CenterChemical Science Program
Functional Nanomaterials Lab (FuNL)
KAUST Catalysis Center (KCC)
KAUST Solar Center (KSC)
Material Science and Engineering
Material Science and Engineering Program
Nanostructured Functional Materials (NFM) laboratory
Physical Science and Engineering (PSE) Division
Surface Science
Ultrafast Laser Spectroscopy and Four-dimensional Electron Imaging Research Group
Date
2020-02-11Online Publication Date
2020-02-11Print Publication Date
2020-03-13Embargo End Date
2021-02-11Submitted Date
2020-01-08Permanent link to this record
http://hdl.handle.net/10754/661562
Metadata
Show full item recordAbstract
Blue-emitting perovskites can be easily attained by precisely tuning the halide ratio of mixed halide (Br/Cl) perovskites (MHPs). However, the adjustable halide ratio hinders the passivation of Cl vacancies, the main source of trap states leading to inferior performance of blue MHP lightemitting diodes (LEDs). Here, we report a strategy for passivating Cl vacancies in MHP quantum dots (QDs) using nonpolar solvent-soluble organic pseudohalide [n-dodecylammonium thiocyanate (DAT)], enabling blue MHP LEDs with greatly enhanced efficiency. Density functional theory calculations reveal that the thiocyanate (SCN−) groups fill in the Cl vacancies and remove electron traps within the bandgap. DAT-treated CsPb(BrxCl1−x)3 QDs exhibit near unity (∼100%) photoluminescence quantum yields, and their blue (∼470 nm) LEDs are spectrally stable with an external quantum efficiency of 6.3%, a record for perovskite LEDs emitting in the range of 460−480 nm relevant to Rec. 2020 display standards, and a halflifetime of ∼99 s.Citation
Zheng, X., Yuan, S., Liu, J., Yin, J., Yuan, F., Shen, W.-S., … Bakr, O. M. (2020). Chlorine Vacancy Passivation in Mixed-Halide Perovskite Quantum Dots by Organic Pseudohalides Enables Efficient Rec. 2020 Blue Light-Emitting Diodes. ACS Energy Letters. doi:10.1021/acsenergylett.0c00057Sponsors
The authors acknowledge the funding support from KAUST, the National Natural Science Foundation of China (Grants 61575136 and 51773141), and the Collaborative Innovation Centre of Suzhou Nano Science and Technology (Nano-CIC) by the Priority Academic Program. E.H.S. and all co-authors from the Department of Electrical and Computer Engineering at the University of Toronto acknowledge the financial support from the Ontario Research Fund−Research Excellence Program and from the Natural Sciences and Engineering Research Council of Canada (NSERC).Publisher
American Chemical Society (ACS)Journal
ACS Energy LettersAdditional Links
https://pubs.acs.org/doi/10.1021/acsenergylett.0c00057ae974a485f413a2113503eed53cd6c53
10.1021/acsenergylett.0c00057