US EPA

4845230 

Journal Article 

Molybdenum substitution simultaneously induced band structure modulation and luminescence enhancement in LiLaMg(W, Mo)O-6: Eu3+ red-emitting phosphor for near ultraviolet excited white light diodes 

Li, Li; Chang, W; He, Jia; Yan, Y; Cui, Min; Jiang, Sha; Xiang, G; Zhou, X 

2018 

Yes 

Journal of Alloys and Compounds
ISSN: 0925-8388 

763 

278-288 

10.1016/j.jallcom.2018.05.306 

WOS:000442484300034 

In this study, LiLaMgW1-xMoxO6: Eu3+ phosphors have been synthesized by high-temperature solid-state reaction method. By changing the W-0 charge transfer (CT) band through Mo6+ substitution, the excitation band of obtained phosphors had been widened largely and could match well with the InGaN-based LED chips. The crystal structure, diffuse reflection spectra, photoluminescent properties of the LiLaMgW1-xMoxO6: 0.1Eu(3+) phosphors were investigated as a function of W/Mo ratio. The red shift of charge transfer band (CTB) was observed with the increase of Mo6+ concentration. Density functional theory (DFT) were performed to calculate the band structure in order to support the excitation band modulation. Moreover, LiLa1-yMgW0.7Mo0.3O6:yEu(3+) phosphors exhibit strong red emission. The excitation, emission spectra, decay dynamics and thermal stability of the phosphors had been measured and investigated in detail. The quenching concentration of Eu3+ is up to 20 mol% and the concentration quenching is attributed to the dipole-dipole interaction. Finally, a white-LED device was fabricated by integrating a mixture of optimal red phosphor, commercial green- and blue-emitting phosphors with a near-ultraviolet (UV) InGaN-based LED chip. The results suggest that the Eu3+-activated LiLaMgW0.7- Mo0.3O6 phosphor is a promising red-emitting phosphor for white-LEDs. (C) 2018 Elsevier B.V. All rights reserved. 

Double perovskite; Charge transfer band; Luminescence; White light-emitting diodes