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  • White light emission from co-doped La 2 Hf 2 O 7 nanoparticles with suppressed host → Eu 3+ energy transfer via a U 6+ co-dopant
Title: White light emission from co-doped La 2 Hf 2 O 7 nanoparticles with suppressed host → Eu 3+ energy transfer via a U 6+ co-dopant
Controlled energy transfer has been found to be one of the most effective ways of designing tunable and white photoluminescent phosphors. Utilizing host emission to achieve the same would lead to a new dimension in the design strategy for novel luminescent materials in solid state lighting and display devices. In this work, we have achieved controlled energy transfer by suppressing the host to dopant energy transfer in La 2 Hf 2 O 7 :Eu 3+ nanoparticles (NPs) by co-doping with uranium ions. Uranium acts as a barrier between the oxygen vacancies of the La 2 Hf 2 O 7 host and Eu 3+ doping ions to increase their separation and reduce the non-radiative energy transfer between them. Density functional theory (DFT) calculations of defect formation energy showed that the Eu 3+ dopant occupies the La 3+ site and the uranium ion occupies the Hf 4+ site. Co-doping the La 2 Hf 2 O 7 :Eu 3+ NPs with uranium ions creates negatively charged lanthanum and hafnium vacancies making the system highly electron rich. Formation of cation vacancies is expected to compensate the excess charge in the U and Eu co-doped La 2 Hf 2 O 7 NPs suppressing the formation of oxygen vacancies. This work shows how one can utilize the full color gamut in the La 2 Hf 2 O 7 :Eu 3+ ,U 6+ NPs with blue, green and red emissions from the host, uranium and europium, respectively, to produce near perfect white light emission.  more » « less
Award ID(s):
1952803 1710160
PAR ID:
10286714
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
Inorganic Chemistry Frontiers
Volume:
8
Issue:
16
ISSN:
2052-1553
Page Range / eLocation ID:
3830 to 3842
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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