Fluorides are promising host materials for optical applications. This paper reports the photoluminescent (PL) and cathodoluminescent (CL) characteristics of barium hexafluorogermanate BaGeF 6 nanowires codoped with Ce 3+ , Tb 3+ and Sm 3+ rare earth ions, produced by a solvothermal route. The synthesized BaGeF 6 nanowires exhibit uniform morphology and size distribution. X-ray diffraction divulges the one-dimensional growth of crystalline BaGeF 6 structure, with the absence of any impurity phases. Visible luminescence is recorded from the nanowires in green and red regions, when the nanowires are codoped with Ce 3+ /Tb 3+ , and Ce 3+ /Tb 3+ /Sm 3+ , respectively, under a UV excitation source. The PL emission from the codoped BaGeF 6 nanowires, when excited by a 254 nm source, originates from the efficient energy transfer bridges between Ce 3+ , Tb 3+ and Sm 3+ ions. The decay time of the visible luminescent emission from the nanowires is in the order of subnanoseconds, being one of the shortest decay time records from inorganic scintillators. The CL emission from the BaGeF 6 nanowires in the tunable visible range reveals their potential use for the detection of high-energy radiation. The PL emissions are sensitive to H 2more »
Dopant site-dependent luminescence from rare-earth doped dibarium octafluorohafnate Ba 2 HfF 8 nanocubes for radiation detection
Development of new host materials containing heavy elements for radiation detection is highly desirable. In this work, dibarium octafluorohafnate, Ba 2 HfF 8 , doped with rare-earth ions, was synthesized as cube-shaped nanocrystals via a facile hydrothermal method. The host lattice contains two Ba 2+ crystallographic sites, and dopants on these sites exhibit site-dependent photoluminescence (PL), cathodoluminescence (CL) and X-ray excited radioluminescence (RL) characteristics. Single doping contents were optimized as 25 mol% Tb 3+ and 5 mol% Eu 3+ . In Ba 2 HfF 8 :Tb 3+ –Eu 3+ codoped nanocrystals, preferrable occupation of Eu 3+ and Tb 3+ at two different Ba 2+ sites in the host lattice was observed. The nanocubes exhibited enhanced emissions over micron sized particles. In PL, the presence of Tb 3+ ions significantly enhanced the emission intensity of Eu 3+ ions due to energy transfer from the Tb 3+ to Eu 3+ ions, while under high-energy irradiation in CL or RL, Tb 3+ emission was intensified. X-ray induced RL with afterglow in seconds was observed. It was found that the codoped sample showed higher sensitivity than the singly doped sample, indicating that codoping is an effective strategy to develop a scintillator with this host more »
- Publication Date:
- NSF-PAR ID:
- 10227098
- Journal Name:
- Journal of Materials Chemistry C
- Volume:
- 9
- Issue:
- 5
- Page Range or eLocation-ID:
- 1721 to 1729
- ISSN:
- 2050-7526
- Sponsoring Org:
- National Science Foundation
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Inorganic materials with short radiative decay time are highly desirable for fast optical sensors. This paper reports fast photoluminescence (PL) from a series of barium hexafluorosilicate (BaSiF 6 ) superlong nanowires with high aspect ratios, codoped with Ce 3+ /Tb 3+ /Eu 3+ ions, with a subnanosecond decay time. Solvothermally synthesized BaSiF 6 nanowires exhibit a uniform morphology, with an average diameter less than 40 nm and aspect ratios of over several hundreds, grown in the c -axis direction with {110} surfaces. The PL emission from the codoped BaSiF 6 nanowires, when excited by a 254 nm source, is dependent on Tb 3+ concentration, and the energy transfer from Ce 3+ to Tb 3+ and to Eu 3+ ions allows efficient emissions in the visible spectra when excited by a near UV source. Annealing BaSiF 6 nanowires at 600 °C in a vacuum produced barium fluoride (BaF 2 ) nanowires composed of nanocrystals. Both BaSiF 6 and BaF 2 nanowires exhibit fast emissions in the visible spectra, with enhanced intensities compared with their codoped microparticle counterparts. The decay time of codoped BaSiF 6 nanowires is found to be shorter than that of codoped BaF 2 nanowires. The energy transfer ismore »
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Accepted Manuscript1.0
- Publisher's Version of Record
- https://doi.org/10.1039/d0tc05051b
