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Title: Pressure-enhanced light emission and its structural origin in Er:GdVO 4

Abstract

Rare earth phosphors have been widely studied because of their sharp emission lines and excellent optical performance. However, photoluminescence (PL) tuning by crystal field in Er3+ embedded phosphors has always been a challenge. Here, we demonstrate that pressure can help to enhance the red and green light emission simultaneously in Er:GdVO4. Synchrotron X-ray diffraction investigations revealed that a structural phase transition was responsible for the enhancement. Our work brightens the future prospects for applications of Er3+-based PL materials in various fields, such as high power lasers and (bio) medical imaging.

Authors:
ORCiD logo; ORCiD logo; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1409584
Report Number(s):
BNL-114636-2017-JA¿¿¿
Journal ID: ISSN 0003-6951
DOE Contract Number:
SC0012704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 110; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Hong, Fang, Yue, Binbin, Cheng, Zhenxiang, Shen, Hui, Yang, Ke, Hong, Xinguo, Chen, Bin, and Mao, Ho-Kwang. Pressure-enhanced light emission and its structural origin in Er:GdVO 4. United States: N. p., 2017. Web. doi:10.1063/1.4973993.
Hong, Fang, Yue, Binbin, Cheng, Zhenxiang, Shen, Hui, Yang, Ke, Hong, Xinguo, Chen, Bin, & Mao, Ho-Kwang. Pressure-enhanced light emission and its structural origin in Er:GdVO 4. United States. doi:10.1063/1.4973993.
Hong, Fang, Yue, Binbin, Cheng, Zhenxiang, Shen, Hui, Yang, Ke, Hong, Xinguo, Chen, Bin, and Mao, Ho-Kwang. Mon . "Pressure-enhanced light emission and its structural origin in Er:GdVO 4". United States. doi:10.1063/1.4973993.
@article{osti_1409584,
title = {Pressure-enhanced light emission and its structural origin in Er:GdVO 4},
author = {Hong, Fang and Yue, Binbin and Cheng, Zhenxiang and Shen, Hui and Yang, Ke and Hong, Xinguo and Chen, Bin and Mao, Ho-Kwang},
abstractNote = {Rare earth phosphors have been widely studied because of their sharp emission lines and excellent optical performance. However, photoluminescence (PL) tuning by crystal field in Er3+ embedded phosphors has always been a challenge. Here, we demonstrate that pressure can help to enhance the red and green light emission simultaneously in Er:GdVO4. Synchrotron X-ray diffraction investigations revealed that a structural phase transition was responsible for the enhancement. Our work brightens the future prospects for applications of Er3+-based PL materials in various fields, such as high power lasers and (bio) medical imaging.},
doi = {10.1063/1.4973993},
journal = {Applied Physics Letters},
number = 2,
volume = 110,
place = {United States},
year = {Mon Jan 09 00:00:00 EST 2017},
month = {Mon Jan 09 00:00:00 EST 2017}
}
  • Microstructural evolution of bias-enhanced grown (BEG) ultrananocrystalline diamond (UNCD) films has been investigated using microwave plasma enhanced chemical vapor deposition in gas mixtures of CH{sub 4} and Ar under different negative bias voltages ranging from −50 to −200 V. Scanning electron microscopy and Raman spectroscopy were used to characterize the morphology, growth rate, and chemical bonding of the synthesized films. Transmission electron microscopic investigation reveals that the application of bias voltage induced the formation of the nanographitic filaments in the grain boundaries of the films, in addition to the reduction of the size of diamond grains to ultra-nanosized granular structured grains.more » For BEG-UNCD films under −200 V, the electron field emission (EFE) process can be turned on at a field as small as 4.08 V/μm, attaining a EFE current density as large as 3.19 mA/cm{sup 2} at an applied field of 8.64 V/μm. But the films grown without bias (0 V) have mostly amorphous carbon phases in the grain boundaries, possessing poorer EFE than those of the films grown using bias. Consequently, the induction of nanographitic filaments in grain boundaries of UNCD films grown in CH{sub 4}/Ar plasma due to large applied bias voltage of −200 V is the prime factor, which possibly forms interconnected paths for facilitating the transport of electrons that markedly enhance the EFE properties.« less
  • Highlights: • Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were identified using XANES and EPR. • Red luminescence was attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. • The Mn{sup 3+} incorporated in the center of AlO{sub 4} tetrahedron was non-luminescent. • The bond-valence theory was used to analyze the effective valences of cations. • A white LED device with CRI up to Ra 93.23 was packaged by using the red phosphor. - Abstract: The synthesis and component of red phosphor, Sr{sub 4}Al{sub 14}O{sub 25}: Mn, were optimized for application in white light-emitting diodes.more » The microstructure and morphology were investigated by the X-ray diffraction and scanning electron microscopy. Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were discriminated using the electron paramagnetic resonance and X-ray absorption near-edge structure spectroscopy techniques. The bond-valence theory was used to analyze the effective valences of Sr{sup 2+} and Al{sup 3+} in Sr{sub 4}Al{sub 14}O{sub 25}. As a result, the strong covalence of Al{sup 3+} in the AlO{sub 4} tetrahedron other than in the AlO{sub 6} octahedron is disclosed. The deep red emission is attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. The mechanism of energy transfer is mainly through dipole–dipole interaction, revealed by the analyses of critical distance and concentration quench. A high color rendering white LED prototype with color-rendering index up to Ra 93.23 packaged by using the red phosphor demonstrates its applicability.« less
  • Single crystals of P{sub 8}W{sub 12}O{sub 52} and its inserted and substituted analogues A{sub x}P{sub 8}W{sub 12}O{sub 52} (A = Li, x = 0.16; A = Na, x = 0.22) and P{sub 8}W{sub 12-x}Mo{sub x}O{sub 52} (x = 0.28, 0.40, 0.68) were prepared, and their electrical resistivities and magnetic susceptibilities were measured. All of these bronzes are found to be isotropic metals. Our tight-binding band electronic structure calculations on P{sub 8}W{sub 12}O{sub 52} show that the three-dimensional metallic character originates from a three-dimensional linking of WO{sub 6} octahedra in the lattice and the relatively high oxidation state of W. Examinationmore » of the structural relationship between P{sub 8}W{sub 12}O{sub 52} and CsP{sub 8}W{sub 8}O{sub 40} led to a new synthetic route for the preparation of CsP{sub 8}W{sub 8}O{sub 40} from P{sub 8}W{sub 12}O{sub 52}. With use of this new method, Tl{sub 2}P{sub 8}W{sub 8}O{sub 40} (isostructural with CsP{sub 8}W{sub 8}O{sub 40}) was synthesized for the first time. 15 refs., 8 figs., 1 tab.« less
  • Tetrameric [(C{sub 5}Me{sub 5})MF{sub 3}{sub 4}] (M = Zr, Hf) react smoothly with Me{sub 3}SiCl in CH{sub 2}Cl{sub 2} at room temperature to give [((C{sub 5}Me{sub 5})ZrF{sub 2}Cl){sub 4}] (1) and [((C{sub 5}Me{sub 5})HfF{sub 2}Cl){sub 4}] (2), respectively in high yield. Treatment of [((C{sub 5}Me{sub 5})MF{sub 3}){sub 4}] (M = Zr, Hf) with Me{sub 2}AlCl in toluene gives mixtures of 1 and [(C{sub 5}Me{sub 5}){sub 4}Zr{sub 4}({mu}-F){sub 2}({mu}-F{sub 2}){sub 2}({mu}-Cl){sub 2}Cl{sub 4}] (3), and 2 and [(C{sub 5}Me{sub 5}){sub 4}Hf{sub 4}({mu}-F){sub 2}({mu}-F{sub 2}){sub 2}({mu}-Cl){sub 2}Cl{sub 4}] (4), respectively, in an approximately 1:1 molar ratio. Metallocene type complexes [(C{sub 5}Me{sub 4}Et){submore » 2}ZrCl{sub 2}] and [(C{sub 5}Me{sub 5}){sub 2}HfCl{sub 2}] react with 1 equiv of Me{sub 3}SnF to give [(C{sub 5}Me{sub 4}Et){sub 2}ZrClF] (5) and [(C{sub 5}Me{sub 5}){sub 2}HfClF] (6), respectively. The complexes 1-6 were characterized by spectroscopic methods ({sup 1}H and {sup 19}F NMR and mass spectrometry). The solid state structures of 1, 3, and 5 were determined by single-crystal X-ray diffraction analyses.« less
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