Photoluminescence studies on holmium (III) and praseodymium (III) doped calcium borophosphate (CBP) phosphors

Prasad, V. Reddy; Damodaraiah, S.; Devara, S.N.; Ratnakaram, Y.C.

doi:10.1016/j.molstruc.2018.02.034

Cited by 28 publications

(9 citation statements)

References 21 publications

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“…3 H i (i = 4, 5, 6) and 3 F j (j=2, 4) (Zhou et al, 2012;Shalapska et al, 2014;Prasad et al, 2018;Runowski et al, 2019). Prasad et al (2018) identified the 1 D 2 state to be the transition origin for the prominent Pr emission at around 600 nm as well as Gaft et al (2005), who also attributed the emission around 500 nm to the same origin. However, the observed positions lie at slightly (around 10 nm) higher emission wavelength that agree better to positions found by e.g.…”

Section: Ree Reference Spectra At 442 Nm Laser Excitationmentioning

confidence: 98%

“…6 and Tab. 3) corresponding to the dominant transitions described by Gaft et al (2005) The transitions originate in 3 P 0 or 3 P 1 (Zhou et al, 2012;Prasad et al, 2018;Runowski et al, 2019), where the comparison between reported and observed emission wavelength indicates that both origins are possible and the (relative)…”

Section: Ree Reference Spectra At 442 Nm Laser Excitationmentioning

confidence: 98%

“…(first, third and fourth emission line) and Zhou et al (2012) (first four emission lines). Additionally, Liang et al(2017),Prasad et al (2018) andRunowski et al (2019) recorded also the emission above 700 nm.…”

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confidence: 92%

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A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

Fuchs¹,

Beyer²,

Lorenz³

et al. 2020

Preprint

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Abstract. With the recurring interest on rare-earth elements (REE), laser-induced fluorescence (LiF) may provide a powerful tool for their rapid and accurate identification at different stages along their value chain. Applications to natural materials such as rocks could complement the spectroscopy-based toolkit for innovative, non-invasive exploration technologies. However, the diagnostic assignment of detected emission lines to individual REE remains challenging, because of the complex composition of natural rocks in which they can be found. The resulting mixed spectra and the large amount of data generated demand for automated approaches of data evaluation, especially in mapping applications such as drill core scanning. LiF reference data provide the solution for robust REE identification, yet they usually remain in the form of tables of published emission lines. We show that a complete reference spectra library could open manifold options for innovative automated analysis. We present a library of high-resolution LiF reference spectra using the Smithsonian rare-earth phosphate standards for electron microprobe analysis.We employ three standard laser wavelengths (325 nm, 442 nm, 532 nm) to record representative spectra in the UV-visible to near-infrared spectral range (340–1080 nm). Excitation at all three laser wavelengths yielded characteristic spectra with distinct REE-related emission lines for EuPO4, TbPO4, DyPO4 and YbPO4. In the other samples, the high-energy excitation at 325 nm caused unspecific, broadband defect emissions. Here, lower energy laser excitation showed successful for suppressing non-REE-related emission. At 442 nm excitation, REE-reference spectra depict the diagnostic emission lines of PrPO4, SmPO4 and ErPO4. For NdPO4 and HoPO4 most efficient excitation was achieved with 532 nm. Our results emphasise on the possibility of selective REE excitation by changing the excitation wavelength according to the suitable conditions for individual REEs. Our reference spectra provide a database for transparent and reproducible evaluation of REE-bearing rocks. The LiF spectral library is available at https://zenodo.org/ and the registered DOI: http://doi.org/10.5281/zenodo.4054606 (Fuchs et al., 2020). It gives access to traceable data for manifold further studies on comparison of emission line positions, emission line intensity ratios and splitting into emission line sub-levels or can be used as reference or training data for automated approaches of component assignment.

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Section: Ree Reference Spectra At 442 Nm Laser Excitationmentioning

confidence: 98%

Section: Ree Reference Spectra At 442 Nm Laser Excitationmentioning

confidence: 98%

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A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

Fuchs¹,

Beyer²,

Lorenz³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…For HoPO 4 , the diagnostic emission line around 540 nm (e.g. Gaft et al, 2005;Qin et al, 2011;Pandey and Swart, 2016) was masked by broad-band luminescence with Ho 3+related absorptions (e.g. Turner et al, 2014;Kokaly et al, 2017) when using 325 and 442 nm laser excitation (see above).…”

Section: Ree Reference Spectra At 532 Nm Laser Excitationmentioning

confidence: 99%

“…The first, relatively weak emission line corresponds to a 5 F 5 to 5 I 8 transition (e.g. Friis et al, 2010;Qin et al, 2011;Pandey and Swart, 2016), while the second, more intense emission cluster results from a 5 F 4 / 5 S 2 to 5 I 7 transition (e.g. Qin et al, 2011;Pandey and Swart, 2016).…”

Section: Ree Reference Spectra At 532 Nm Laser Excitationmentioning

confidence: 99%

A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

Fuchs

Beyer

Lorenz

et al. 2021

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. With the recurring interest in rare earth elements (REEs), laser-induced fluorescence (LiF) may provide a powerful tool for their rapid and accurate identification at different stages along their value chain. Applications to natural materials such as minerals and rocks could complement the spectroscopy-based toolkit for innovative, non-invasive exploration technologies. However, the diagnostic assignment of detected emission lines to individual REEs remains challenging because of the complex composition of natural rocks in which they can be found. The resulting mixed spectra and the large amount of data generated demand automated approaches of data evaluation, especially in mapping applications such as drill core scanning. LiF reference data provide the solution for robust REE identification, yet they usually remain in the form of tables of published emission lines. We show that a complete reference spectra library could open manifold options for innovative automated analysis. We present a library of high-resolution LiF reference spectra using the Smithsonian rare earth phosphate standards for electron microprobe analysis. We employ three standard laser wavelengths (325, 442, 532 nm) to record representative spectra in the UV-visible to near-infrared spectral range (340–1080 nm). Excitation at all three laser wavelengths yielded characteristic spectra with distinct REE-related emission lines for EuPO4, TbPO4, DyPO4 and YbPO4. In the other samples, the high-energy excitation at 325 nm caused unspecific, broad-band defect emissions. Here, lower-energy laser excitation is shown to be successful for suppressing non-REE-related emission. At 442 nm excitation, REE reference spectra depict the diagnostic emission lines of PrPO4, SmPO4 and ErPO4. For NdPO4 and HoPO4 the most efficient excitation was achieved with 532 nm. Our results emphasise the possibility of selective REE excitation by changing the excitation wavelength according to the suitable conditions for individual REEs. Our reference spectra provide a database for the transparent and reproducible evaluation of REE-bearing rocks. The LiF spectral library is available at zenodo.org and the registered DOI https://doi.org/10.5281/zenodo.4054606 (Fuchs et al., 2020). Primarily addressing the raw material exploration sector, it aids particularly the development of advanced data processing routines for LiF analysis but can also support further research on the REE luminescence in natural rocks or artificial compounds. It gives access to traceable data for the comparison of emission line positions, emission line intensity ratios and splitting into emission line sub-levels or can be used as reference or training data for automated approaches of component assignment.

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Microwave‐assisted synthesis of praseodymium (Pr)‐doped ZnS QDs such as nanoparticles for optoelectronic applications

et al. 2023

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Pr‐doped ZnS nanoparticles were synthesised using a low‐cost microwave assisted technique and investigations on their structure, morphology, optical properties, Raman resonance, dielectric properties and luminescence were conducted. Broad XRD peaks suggested the formation of low‐dimensional Pr‐doped ZnS nanoparticles with a cubic structure which was validated by TEM/HRTEM analysis. The energy gaps were identified using diffuse reflectance spectroscopy and it was found that the values varied between 3.54 and 3.61 for different samples. Vibrational experiments on Pr doped ZnS nanoparticles revealed significant Raman modes at ~ 270 and ~350 cm ‐1 associated to TO and LO modes that are shifted to lower wavenumbers, indicating phonon confinement in the synthesised products. The PL spectra of all samples demonstrate that the pure and Pr doped ZnS nanoparticles are three level laser active materials. EDX and mapping study confirms the homogeneous presence of Pr in ZnS. TEM study shows that the particles are of very small size and cubic phase. The samples have high dielectric constant values between 13 and 24 and low loss values, according to the dielectric analysis. With an increase in frequency and a change in the Pr content of ZnS, an intense peak can be seen in the PL spectra at a wavelength of 360 nm, and some other peaks observed correspond to the transition of Pr 3+. The produced NPs are appropriate for optoelectronic applications due to their short dimension, high energy gap, high dielectric constant and low loss values.

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Photoluminescence studies on holmium (III) and praseodymium (III) doped calcium borophosphate (CBP) phosphors

Cited by 28 publications

References 21 publications

A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification

Microwave‐assisted synthesis of praseodymium (Pr)‐doped ZnS QDs such as nanoparticles for optoelectronic applications

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