Achieving broadband near-infrared luminescence in Cr3+-Activated Y2Mg2Al2Si2O12 phosphors via multi-site occupancy

Gui-Hua Li; Han-Qi Wei; Qi-Hua Yang; Zhi-Wei Luo; Ge-Mei Cai; Li Ma; Xiao-Jun Wang

Advanced Powder Materials (Jun 2024)

Achieving broadband near-infrared luminescence in Cr3+-Activated Y2Mg2Al2Si2O12 phosphors via multi-site occupancy

Gui-Hua Li,
Han-Qi Wei,
Qi-Hua Yang,
Zhi-Wei Luo,
Ge-Mei Cai,
Li Ma,
Xiao-Jun Wang

Affiliations

Gui-Hua Li: School of Materials Science and Engineering, Central South University, Changsha 410083, China; Science Center for Phase Diagram & Materials Design and Manufacture, Central South University, Changsha 410083, China
Han-Qi Wei: School of Materials Science and Engineering, Central South University, Changsha 410083, China; Science Center for Phase Diagram & Materials Design and Manufacture, Central South University, Changsha 410083, China
Qi-Hua Yang: School of Materials Science and Engineering, Central South University, Changsha 410083, China; Science Center for Phase Diagram & Materials Design and Manufacture, Central South University, Changsha 410083, China
Zhi-Wei Luo: School of Materials Science and Engineering, Central South University, Changsha 410083, China
Ge-Mei Cai: School of Materials Science and Engineering, Central South University, Changsha 410083, China; Science Center for Phase Diagram & Materials Design and Manufacture, Central South University, Changsha 410083, China; Corresponding author. School of Materials Science and Engineering, Central South University, Changsha 410083, China.
Li Ma: Department of Physics, Georgia Southern University, Statesboro, GA 30460, United States
Xiao-Jun Wang: Department of Physics, Georgia Southern University, Statesboro, GA 30460, United States; Corresponding author.

Journal volume & issue: Vol. 3, no. 3
p. 100186

Abstract

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Cr3+-activated near-infrared (NIR) phosphors are key for NIR phosphor-converted light emitting diodes (NIR pc-LED). While, the site occupancy of Cr3+ is one of the debates that have plagued researchers. Herein, Y2Mg2Al2Si2O12 (YMAS) with multiple cationic sites is chosen as host of Cr3+ to synthesize YMAS: xCr3+ phosphors. In YMAS, Cr3+ ions occupy simultaneously Al/SiO4 tetrahedral, Mg/AlO6 octahedral, and Y/MgO8 dodecahedral sites which form three luminescent centers named as Cr1, Cr2, and Cr3, respectively. Cr1 and Cr2 relate to an intermediate crystal field, with transitions of 2E→4A2 and 4T2→4A2 occurring simultaneously. As Cr3+ concentration increases, the 4T2→4A2 transition becomes more pronounced in Cr1 and Cr2, resulting in a red-shift and broadband emission. Cr3 consistently behaves a weak crystal field and exhibits the broad and long-wavelength emission. Wide-range NIR emission centering at 745 nm is realized in YMAS: 0.03Cr3+ phosphor. This phosphor has high internal quantum efficiency (IQE = 86%) and satisfying luminescence thermal stability (I423 K = 70.2%). Using this phosphor, NIR pc-LEDs with 56.6 mW@320 mA optical output power is packaged and applied. Present study not only demonstrates the Cr3+ multi-site occupancy in a certain oxide but also provides a reliable approach via choosing a host with diverse cationic sites and local environments for Cr3+ to achieve broadband NIR phosphors.

Published in Advanced Powder Materials

ISSN: 2772-834X (Online)
Publisher: KeAi Communications Co. Ltd.
Country of publisher: China
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.keaipublishing.com/en/journals/advanced-powder-materials/

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