Effect of particle size and dopant concentration on photophysical properties of Eu3+-doped rare earth oxysulphide phosphor coatings

Chakradhar, R.P.S.; Basu, Bharathibai J.; Lakshmi, R.V.

doi:10.1016/j.saa.2010.12.018

Cited by 13 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The signal intensities of the Eu-activated phosphors increased by a factor of 2 to 4 when the PMMA fiber-optic cable was shortened from 15 m to 0 m. The signal intensity could potentially be further increased if the ISDs incorporated phosphors with parameters optimized for maximal light yield, as the light yield depends on both the Eu ion concentration (Yen et al 2007) and the particle size (Chakradhar et al 2011, Nakamura et al 2014). Studies have shown that Eu-activated phosphor crystals with 10- to 100-nm particle sizes exhibit larger scintillation yields than do micrometer-sized crystals (Wakefield et al 2001, Osseni et al 2011).…”

Section: Discussionmentioning

confidence: 99%

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Kertzscher

Beddar

2017

Phys. Med. Biol.

View full text Add to dashboard Cite

The availability of real-time treatment verification during high-dose-rate (HDR) brachytherapy is currently limited. Therefore, we studied the luminescence properties of the widely commercially available scintillators using the inorganic materials Eu-activated phosphors Y2O3:Eu, YVO4:Eu, Y2O2S:Eu, and Gd2O2S:Eu to determine whether they could be used to accurately and precisely verify HDR brachytherapy doses in real time. The suitability for HDR brachytherapy of inorganic scintillation detectors (ISDs) based on the 4 Eu-activated phosphors in powder form was determined based on experiments with a 192Ir HDR brachytherapy source. The scintillation intensities of the phosphors were 16 to 134 times greater than that of the commonly used organic plastic scintillator BCF-12. High signal intensities were achieved with an optimized packing density of the phosphor mixture and with a shortened fiber-optic cable. The influence of contaminating Cerenkov and fluorescence light induced in the fiber-optic cable (stem signal) was adequately suppressed by inserting between the fiber-optic cable and the photodetector a 25-nm band-pass filter centered at the emission peak. The spurious photoluminescence signal induced by the stem signal was suppressed by placing a long-pass filter between the scintillation detector volume and the fiber-optic cable. The time-dependent luminescence properties of the phosphors were quantified by measuring the non-constant scintillation during irradiation and the afterglow after the brachytherapy source had retracted. We demonstrated that a mixture of Y2O3:Eu and YVO4:Eu suppressed the time-dependence of the ISDs and that the time-dependence of Y2O2S:Eu and Gd2O2S:Eu introduced large measurement inaccuracies. We conclude that ISDs based on a mixture of Y2O3:Eu and YVO4:Eu are promising candidates for accurate and precise real-time verification technology for HDR BT that is cost effective and straightforward to manufacture. Widespread dissemination of this technology could lead to an improved understanding of error types and frequencies during BT and to improved patient safety during treatment.

show abstract

Section: Discussionmentioning

confidence: 99%

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Kertzscher

Beddar

2017

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…Introduction Europium-doped rare earth (RE) oxysulphide phosphors have received considerable attention as red-emitting phosphors for their applications in X-ray intensifying screens and cathode ray screens for TV sets. [1] Compared to sulphides, oxysulphides are more efficient phosphors as they have a wide excitation band which increases the luminescence output. [2] Due to their smaller dimension and lower excitation wavelength, the nanophosphors have higher luminescence efficiency and better resolution which makes them ideal for display devices.…”

mentioning

confidence: 99%

Spectral and trapping parameters of Eu³⁺in Gd₂O₂S nanophosphor

Som

Choubey

Sharma

2013

Journal of Experimental Nanoscience

View full text Add to dashboard Cite

This paper reports the structural, photometric, spectral and trapping parameters of Eu 3þ -doped gadolinium oxysulphide nanophosphor. The X-ray diffraction (XRD) data show the presence of the hexagonal phase of Gd 2 O 2 S and a crystallite size in nanometre range. Different structural parameters were calculated from XRD data. The Fourier transform infrared (FTIR) spectrum also confirms the formation of a compound. Scanning electron microscope studies reveal the morphology and crystallite size of the prepared phosphor. The band gap of the phosphor was calculated from diffuse reflectance spectra using the Kubelka-Munk function at 4.76 eV. The phosphor was illuminated with ultraviolet light and shows the characteristic red luminescence corresponding toThe Judd-Ofelt intensity parameters and spectral parameters were estimated from the photoluminescence data. The nanophosphor was irradiated with g-rays in the dose range 15-50 Gy for thermoluminescence (TL) studies and a shifting of the peak towards lower temperatures was observed with increasing g-dose. Trapping parameters were calculated from TL data using various glow curve analysis methods.

show abstract

“…UC ytterbium- and erbium-doped sodium yttrium fluoride powder has a particle size of 1–5 μm and is optimized to absorb in the wavelength range of 940–980 nm; the resulting PDMS-YbEr composite has been previously demonstrated in fiber optic temperature sensors [ 16 ]. Oxysulphide powder (GOS:Eu) has a mean particle size of 2–3 μm, exhibits a wide excitation band located in the UV region with a maximum absorption peak around 345 nm and has been shown to be useful for coatings in sensing and imaging applications [ 19 , 20 ]. As described elsewhere [ 21 ] and as shown in the following sections, the resulting PDMS-GOS:Eu composite provides attractive features such as a UV-fluorescence sensing material for fiber optic sensors.…”

Section: Methodsmentioning

confidence: 99%

“…The luminescence response of these composites is of great interest because they have shown great potential for monitoring UV emissions from biochemical species [ 20 , 21 ]. Because cluster formation and bulkiness can lead to a decrease in luminescence for these powders [ 19 , 24 ], we explored the performance of PDMS-GOS:Eu composites by fabricating membranes with different thicknesses. This was achieved through adjustments of the velocity ( v c ) and the spinning time ( t vc ) of the spin coater [ 21 , 25 ]; the thicknesses of the membranes were subsequently measured with a micrometer (IP65, 293-348-30, Mitutoyo).…”

Section: Polymer Composite Membrane Characterizationmentioning

confidence: 99%

Luminescent Polymer Composites for Optical Fiber Sensors

2023

View full text Add to dashboard Cite

Optical fiber sensors incorporating luminescent materials are useful for detecting physical parameters and biochemical species. Fluorescent materials integrated on the tips of optical fibers, for example, provide a means to perform fluorescence thermometry while monitoring the intensity or the spectral variations of the fluorescence signal. Similarly, certain molecules can be tracked by monitoring their characteristic emission in the UV wavelength range. A key element for these sensing approaches is the luminescent composite, which may be obtained upon allocating luminescent nanomaterials in glass or polymer hosts. In this work, we explore the fluorescence features of two composites incorporating lanthanide-doped fluorescent powders using polydimethylsiloxane (PDMS) as a host. The composites are obtained by a simple mixing procedure and can be subsequently deposited onto the end faces of optical fibers via dip coating or molding. Whereas one of the composites has shown to be useful for the fabrication of fiber optic temperature sensors, the other shows promising result for detection of UV radiation. The performance of both composites is first evaluated for the fabrication of membranes by examining features such as fluorescent stability. We further explore the influence of parameters such as particle concentration and density on the fluorescence features of the polymer blends. Finally, we demonstrate the incorporation of these PDMS fluorescent composites onto optical fibers and evaluate their sensing capabilities.

show abstract

Effect of particle size and dopant concentration on photophysical properties of Eu3+-doped rare earth oxysulphide phosphor coatings

Cited by 13 publications

References 16 publications

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Spectral and trapping parameters of Eu³⁺in Gd₂O₂S nanophosphor

Luminescent Polymer Composites for Optical Fiber Sensors

Contact Info

Product

Resources

About

Effect of particle size and dopant concentration on photophysical properties of Eu3+-doped rare earth oxysulphide phosphor coatings

Cited by 13 publications

References 16 publications

Inorganic scintillation detectors based on Eu-activated phosphors for192Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for192Ir brachytherapy

Spectral and trapping parameters of Eu3+in Gd2O2S nanophosphor

Luminescent Polymer Composites for Optical Fiber Sensors

Contact Info

Product

Resources

About

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Spectral and trapping parameters of Eu³⁺in Gd₂O₂S nanophosphor