Li substituent tuning of LED phosphors with enhanced efficiency, tunable photoluminescence, and improved thermal stability

Ming Zhao; Zhiguo Xia; Xiaoxiao Huang; Lixin Ning; Romain Gautier; Maxim S Molokeev; Yayun Zhou; Yu-Chun Chuang; Qinyuan Zhang; Quanlin Liu; Kenneth R Poeppelmeier

doi:10.1126/sciadv.aav0363

Li substituent tuning of LED phosphors with enhanced efficiency, tunable photoluminescence, and improved thermal stability

Sci Adv. 2019 Jan 11;5(1):eaav0363. doi: 10.1126/sciadv.aav0363. eCollection 2019 Jan.

Authors

Ming Zhao¹, Zhiguo Xia^{1

2}, Xiaoxiao Huang³, Lixin Ning³, Romain Gautier⁴, Maxim S Molokeev^{5

6

7}, Yayun Zhou², Yu-Chun Chuang⁸, Qinyuan Zhang², Quanlin Liu¹, Kenneth R Poeppelmeier⁹

Affiliations

¹ The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
² State Key Laboratory of Luminescent Materials and Devices and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641, China.
³ Anhui Key Laboratory of Optoelectric Materials Science and Technology, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Normal University, Wuhu, Anhui 241000, China.
⁴ Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes, Cedex 03, France.
⁵ Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.
⁶ Siberian Federal University, Krasnoyarsk 660041, Russia.
⁷ Department of Physics, Far Eastern State Transport University, Khabarovsk 680021, Russia.
⁸ National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan.
⁹ Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA.

Abstract

Solid-state phosphor-converted white light-emitting diodes (pc-WLEDs) are currently revolutionizing the lighting industry. To advance the technology, phosphors with high efficiency, tunable photoluminescence, and high thermal stability are required. Here, we demonstrate that a simple lithium incorporation in NaAlSiO₄:Eu system enables the simultaneous fulfillment of the three criteria. The Li substitution at Al sites beside Na sites in NaAlSiO₄:Eu leads to an enhanced emission intensity/efficiency owing to an effective Eu³⁺ to Eu²⁺ reduction, an emission color tuning from yellow to green by tuning the occupation of different Eu sites, and an improvement of luminescence thermal stability as a result of the interplay with Li-related defects. A pc-WLED using the Li-codoped NaAlSiO₄:Eu as a green component exhibits improved performance. The phosphors with multiple activator sites can facilitate the positive synergistic effect on luminescence properties.