Impact of charge compensation on optical and thermometric behaviour of titanate phosphors

Pattnaik, Sasank; Kumar, Vineet

doi:10.1016/j.materresbull.2019.110761

Cited by 53 publications

(35 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…32 The reduction in the slope value from 'n B 2' in the co-doped phosphors is due to non-radiative relaxation, energy transfer, a cooperative energy transfer process, etc. 2,33,34 In the case of co-doped phosphors, the UC intensity increases and decreases after 694 mW of pump power due to saturation effect. So, no enhancement in the UC emission intensity beyond that pump power is noticed.…”

Section: Uc Emission Studymentioning

confidence: 99%

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Uc Emission Studymentioning

confidence: 99%

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Generally speaking, according to the Arrhenius law, the luminescence intensity of rare earth ions should be reduced at high temperature caused by the thermal quenching. [47][48][49][50][51] However, as shown in Figure S3, the absolute intensity of 4 I 13/2 → 4 I 15/2 transition is enhanced with the rising temperature, which is caused by the acceleration of the MPR process from 4 I 11/2 level to 4 I 13/2 level under high temperature. 52 The abnormal negative thermal quenching behavior of the 4 in Figure S4.…”

Section: Optical Thermometrymentioning

confidence: 99%

Ultrasensitive optical thermometer based on abnormal thermal quenching Stark transitions operating beyond 1500 nm

et al. 2021

View full text Add to dashboard Cite

Light with wavelength longer than 1500 nm has great potential to afford deep biotissue penetration due to its extremely weak photon scattering and undetectable autofluorescence in vivo. Here, in order to satisfy the requirements for thermometry during the tumor hyperthermia process, an ultrasensitive optical thermometer operating beyond 1500 nm is developed by employing the thermally coupled Stark sublevels of Er 3+ : 4 I 13/2 → 4 I 15/2 transition based on fluorescence intensity ratio (FIR) technology in Yb 3+ and Er 3+ codoped BaY 2 O 4 . Compared with the typical upconversion (UC) material β-NaYF 4 : Yb 3+ /Er 3+ and Y 2 O 3 : Yb 3+ /Er 3+ , BaY 2 O 4 : Yb 3+ /Er 3+shows more intense red Er 3+ : 4 F 9/2 → 4 I 15/2 transition and 1.5 μm near-infrared (NIR) Er 3+ : 4 I 13/2 → 4 I 15/2 transition induced by its larger phonon energy and higher quenching concentration of Er 3+ . An equivalent four-level model is proposed to investigate the temperature characteristics of the NIR emission, from which four Stark transitions are separated from the raw spectra, named α, β, γ, and δ respectively. Then, the NIR thermal sensing performance have been developed by utilizing the FIR of I β to I α and I γ to I α . More importantly, an ultra-high sensitivity for optical thermometry has been obtained through the combination of transition β and γ, especially in the physiological temperature region. Furthermore, the detection depth of NIR light in bio-tissues is assessed by an ex vivo test, demonstrating that the maximal detection depth of NIR emission can reach to 8 mm without any influence on optical thermometry. These findings indicate that Yb 3+ and Er 3+ codoped BaY 2 O 4 is a remarkable contender for optical thermometry in deep tissue with ultra-high sensitivity. K E Y W O R D S1.5 μm emission, energy transfer, Stark sublevel, temperature sensing, upconversion | 5785 XIANG et Al.

show abstract

“…Based on Blasse's theory, [45][46][47][48][49] the critical distance (R c ) of xEu 3+ phosphor, the values of N, X c and V were 8, 0.03, and 377.841 Å 3 respectively. From the above equation, the critical energy transfer distance was estimated to be about 14.079 Å, which was greater than 5 Å.…”

Section: Photoluminescence Spectral Analysismentioning

confidence: 99%

Synthesis and characterization of a Eu³⁺‐activated Ba_2–xV₂O₇:xEu³⁺ phosphor using a hydrothermal method: a potential material for near‐UV‐WLED applications

Bharathi¹,

Jeyakumaran²,

Ramaswamy³

et al. 2021

Luminescence

View full text Add to dashboard Cite

Eu 3+ -activated Ba 2 V 2 O 7 (Ba 2-x V 2 O 7 :xEu 3+ ) phosphor materials were synthesized using a hydrothermal method and different concentrations of europium (x = 0.01, 0.02, 0.03, 0.04, and 0.05%). Phase purity, structural, morphological, optical, and luminescence characteristics of the as-synthesized phosphors were studied using powder X-ray diffraction (XRD), high resolution scanning electron microscopy, UV-visible spectroscopy, and fluorescence spectrometry. The recorded XRD patterns of the as-synthesized phosphors were indexed and predicted to be a triclinic structure. A cube-like morphology was obtained for the as-prepared samples. Broad absorption in the UV region from 200 nm to 380 nm was observed and the good transparency in the visible region at 400-800 nm originated from the [VO 4 ] 3− group charge transfer (CT) transition. The broad emission peak centred at 499 nm was due to the CT band of the [VO 4 ] 3− group. Also, a sharp peak observed at 613 nm was due to the electric dipole transition of 5 D 0 ! 7 F 2 of Eu 3+ ions that occupied the lattice sites without inversion symmetry for all concentrations. The colour qualities of the as-prepared samples were calculated using Commission International de l'Eclairage coordinates. The colour-rending index (CRI) value was 86 for the Ba 1.97 V 2 O 7 :0.03Eu 3+ phosphor. Furthermore, a WLED with a high CRI value of 95 was achieved by coupling the 3 W 356 nm near-UV light-emitting diode (LED) chip with the Ba 2-x V 2 O 7 :xEu 3+ phosphor. These results suggested that the as-prepared phosphor materials are potential candidates for fabrication of near-UV chip excited WLEDs.

show abstract

Impact of charge compensation on optical and thermometric behaviour of titanate phosphors

Cited by 53 publications

References 45 publications

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

Ultrasensitive optical thermometer based on abnormal thermal quenching Stark transitions operating beyond 1500 nm

Synthesis and characterization of a Eu³⁺‐activated Ba_2–xV₂O₇:xEu³⁺ phosphor using a hydrothermal method: a potential material for near‐UV‐WLED applications

Contact Info

Product

Resources

About

Impact of charge compensation on optical and thermometric behaviour of titanate phosphors

Cited by 53 publications

References 45 publications

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

Ultrasensitive optical thermometer based on abnormal thermal quenching Stark transitions operating beyond 1500 nm

Synthesis and characterization of a Eu3+‐activated Ba2–xV2O7:xEu3+ phosphor using a hydrothermal method: a potential material for near‐UV‐WLED applications

Contact Info

Product

Resources

About

Synthesis and characterization of a Eu³⁺‐activated Ba_2–xV₂O₇:xEu³⁺ phosphor using a hydrothermal method: a potential material for near‐UV‐WLED applications