Enhanced blue-light excited cyan-emitting persistent luminescence of BaLu2Al2Ga2SiO12:Ce3+, Bi3+ phosphors for AC-LEDs via defect modulation

Weihong Yuan; Ran Pang; Shangwei Wang; Tao Tan; Chengyu Li; Chaowei Wang; Hongjie Zhang

doi:10.1038/s41377-022-00868-8

Enhanced blue-light excited cyan-emitting persistent luminescence of BaLu₂Al₂Ga₂SiO₁₂:Ce³⁺, Bi³⁺ phosphors for AC-LEDs via defect modulation

Light Sci Appl. 2022 Jun 17;11(1):184. doi: 10.1038/s41377-022-00868-8.

Authors

Weihong Yuan^{1

2}, Ran Pang³, Shangwei Wang¹, Tao Tan², Chengyu Li^{4

5

6}, Chaowei Wang¹, Hongjie Zhang^{1

7}

Affiliations

¹ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
² University of Science and Technology of China, Hefei, 230026, China.
³ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. pangran@ciac.ac.cn.
⁴ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. cyli@ciac.ac.cn.
⁵ University of Science and Technology of China, Hefei, 230026, China. cyli@ciac.ac.cn.
⁶ Zhongke Rare Earth (Guangzhou) Co., Ltd, Guangzhou, 510700, China. cyli@ciac.ac.cn.
⁷ Zhongke Rare Earth (Guangzhou) Co., Ltd, Guangzhou, 510700, China.

Abstract

Alternating current light-emitting diodes (AC-LEDs) have received significant attention from both academia and industry due to their remarkable benefits of more compact volume, cheaper manufacturing cost, greater energy usage efficiency, and longer service life. One of the most significant challenges for AC-LEDs is the flicker effect, which is mainly caused by the unavoidable 5-20 ms dimming time. Aiming to reduce the flicker effect, we designed a series of excellent blue-light excited cyan-emitting persistent luminescence (PersL) phosphors BaLu₂Al₂Ga₂SiO₁₂:Ce³⁺, Bi³⁺ via defect engineering of co-doping Bi³⁺. Interestingly, we found that co-doping Bi³⁺ not only effectively enhanced the PersL intensity, but also regulated the PersL lifetime of this phosphors. As the Bi³⁺ co-doping concentration increases to 0.01, the τ₈₀ value (the time when the PersL intensity decreases to 80% of the initial intensity) increases from 0.24 to 19.61 ms, which proves to be effective in compensating the flicker effect of AC-LEDs. A new method of generating white light emission during the dimming time through adding the blue-light excited cyan PersL phosphor to the original orange-red PersL phosphor was proposed and an AC-LED lamp with a decreased percent flicker of 48.15% was fabricated, which is significantly better than the other currently reported AC-LED devices based on PersL phosphors. These results demonstrate that BaLu₂Al₂Ga₂SiO₁₂:Ce³⁺, Bi³⁺ might be an attractive material for low-flicker AC-LEDs.