近日，兰州大学的Takatoshi Seto&王育华及其研究团队取得一项新进展。经过不懈努力，他们提出用于产生更亮长余辉发光的电场激励技术。相关研究成果已于2024年7月15日在国际知名学术期刊《光：科学与应用》上发表。

据悉，对长余辉发光(PersL)机制的不成熟理解阻碍了新型长余辉发光材料(PersLMs)的发展。为此，该研究团队在SrAl₂O₄:Eu²⁺,Dy³⁺荧光粉和电极组成的层状结构上进行了原位直流电场测量。在本研究中，通过分析电流信号和热释光(TL)光谱，研究了光致发光(PL)和余辉特性与电压的关系。PersL的强度增加是由于一种被称为“外电场激励的余辉初始亮度增强”的新现象。

研究人员利用速率方程方法说明了这一动力学过程，其中0.022eV超浅势阱捕获的电子可以在长余辉期间通过导带转移。在6V电压下，余辉强度可达0.538cdm^-2。电场激励技术的设计能够增强PersLMs的强度，并为探索某些已建立的PersLMs的基本机制提供了新的视角。

附：英文原文

Title: Electrical stimulation for brighter persistent luminescence

Author: Ma, Xilin, Wang, Yuhua, Seto, Takatoshi

Issue&Volume: 2024-07-15

Abstract: An immature understanding of the mechanisms of persistent luminescence (PersL) has hindered the development of new persistent luminescent materials (PersLMs) with increased brightness. In this regard, in-situ direct current (DC) electric field measurements were conducted on a layered structure composed of the SrAl₂O₄:Eu²⁺,Dy³⁺ phosphor, and an electrode. In this study, the photoluminescence (PL) and afterglow properties were investigated with respect to voltage by analyzing the current signal and thermoluminescence (TL) spectroscopy. The intensity of PersL increased due to a novel phenomenon known as “external electric field stimulated enhancement of initial brightness of afterglow”. This dynamic process was illustrated via the use of a rate equation approach, where the electrons trapped by the ultra-shallow trap at 0.022eV could be transferred through the conduction band during long afterglow. The afterglow intensity could reach 0.538cdm^-2 at a 6V electric voltage. The design of an electric field stimulation technique enables the enhancement of the intensity of PersLMs and provides a new perspective for exploring the fundamental mechanics of certain established PersLMs.

DOI: 10.1038/s41377-024-01507-0

Source: https://www.nature.com/articles/s41377-024-01507-0