Efficient Broadband Yellow-Green Emission of Vacancy Halide Double Perovskites Through the Ion-Exchanged Strategy

Ruxin Liu; Jing Yang; Di Zhao; Wenjing Liu; Guojing Li; Wenbo Yan; Wenjun Zhang

doi:10.1021/acs.inorgchem.1c02473

Efficient Broadband Yellow-Green Emission of Vacancy Halide Double Perovskites Through the Ion-Exchanged Strategy

Inorg Chem. 2021 Dec 6;60(23):17878-17888. doi: 10.1021/acs.inorgchem.1c02473. Epub 2021 Nov 16.

Authors

Ruxin Liu¹, Jing Yang^{1

2}, Di Zhao¹, Wenjing Liu¹, Guojing Li¹, Wenbo Yan³, Wenjun Zhang¹

Affiliations

¹ School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, P. R. China.
² School of Materials Science and Engineering, Hebei University of Engineering, Handan, Hebei province 056038, P. R. China.
³ School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, P. R. China.

PMID: 34784481
DOI: 10.1021/acs.inorgchem.1c02473

Abstract

Broadband high-efficiency luminescent materials have become a hot spot in lead-free perovskite research. There are relatively few broadband yellow-green phosphors with both ultraviolet and blue excitation ranges, which make them more suitable for phosphor-converted white LEDs. Through the ion-exchanged strategy, Cs₂Hf_1-xTe_xCl₆ (CH_1-xT_xC) vacancy halide double perovskites were successfully prepared at room temperature. Using different excitation ranges of CH_1-xT_xC, two types of high-quality white LEDs are obtained. By combining density functional theory calculations and experiments, it is proved that this bright broadband yellow-green emission (photoluminescence quantum yield of 83.46%) is not only derived from the ion transitions of Te⁴⁺ but also exhibits the inherent characteristics of self-trapped exciton emission. Our results not only broaden the application fields of lead-free halide perovskites but also provide further insights into the luminescence mechanism.