Mechanism of the trivalent lanthanides\u2019 persistent luminescence in wide bandgap materials

Leipeng Li,Chongyang Cai,Baolai Liang,Yunqian Li,Jianrong Qiu,Tianyi Li,Yue Hu,Xuefeng Zhang,Yanmin Yang

doi:10.1038/s41377-022-00736-5

Abstract

The trivalent lanthanides have been broadly utilized as emitting centers in persistent luminescence (PersL) materials due to their wide emitting spectral range, which thus attract considerable attention over decades. However, the origin of the trivalent lanthanides’ PersL is still an open question, hindering the development of excellent PersL phosphors and their broad applications. Here, the PersL of 12 kinds of the trivalent lanthanides with the exception of La3+, Lu3+, and Pm3+ is reported, and a mechanism of the PersL of the trivalent lanthanides in wide bandgap hosts is proposed. According to the mechanism, the excitons in wide bandgap materials transfer their recombination energy to the trivalent lanthanides that bind the excitons, followed by the generation of PersL. During the PersL process, the trivalent lanthanides as isoelectronic traps bind excitons, and the binding ability is not only related to the inherent arrangement of the 4f electrons of the trivalent lanthanides, but also to the extrinsic ligand field including anion coordination and cation substitution. Our work is believed to be a guidance for designing high-performance PersL phosphors.

Highlights

Persistent luminescence (PersL) phosphors can continue to emit light for seconds and even longer after the stoppage of excitation
Li et al Light: Science & Applications (2022)11:51 is difficult to put forward a universal mechanism to reasonably explain all experimental results, and here we mainly focus on the PersL of the trivalent lanthanides in wide bandgap hosts due to its extensive application value[20]
Except for La3+ without the 4f electrons and Lu3+ with full filled 4f shell and radioactive Pm3+, the rest trivalent lanthanides’ PersL was observed with success in the selected hosts NaYF4, Cs2NaYF6, YPO4, and ScPO4 (Fig. 1a, Supplementary Fig. S1)

Summary

Introduction

Persistent luminescence (PersL) phosphors can continue to emit light for seconds and even longer after the stoppage of excitation. Due to this attractive feature, PersL phosphors have a wide range of applications in the fields of display, anti-counterfeiting, information storage, biological labeling, etc.[1–8]. The commonly used luminescent centers that can generate PersL include lanthanide series, transition metal elements, and other ions such as Bi3+9–15. The latter two kinds of luminescent centers are generally limited to their relatively narrow emitting spectral bands, mainly in the visible spectral range.

Methods

Results

Discussion

Conclusion