A comparative study on the crystal phases and their respective luminescence behaviour of Gd3+ based host materials such as GdPO4, GdF3, GdVO4 and Gd2O3 sensitized with 7at.% Ce3+ and activated with 5 at.% Tb3+ have been reported. The nanomaterials were prepared by polyol method using ethylene glycol as solvent and found to have different crystal structures such as monoclinic, orthorhombic, tetragonal and cubic phase. Clear characteristics emission from Tb3+ has been observed in all the samples when excited in the absorption wavelength of Ce3+ and Gd3+ (∼280 nm). Among all the above materials, intense emission of Tb3+ is found in GdPO4 followed by GdF3, Gd2O3 and GdVO4 respectively. The Tb3+ emission is strongly influenced by the energy transfer process and crystal structure of the host materials and hence this study will be important for choosing suitable materials for display devices and biomedical applications. © 2018 Author(s).

Rani C

Department of Electrical Engineering

School of Electrical Engineering

Vellore Campus

Niroj Kumar Sahu

Centre for Nanotechnology Research

Jadhao C.V

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

A comparative study on the luminescence properties of Ce3+/Tb3+ doped Gd-based host nanomaterials

AIP Conference Proceedings

ACS Photonics

Ce3+-Sensitized GdPO4:Tb3+ Nanorods: An Investigation on Energy Transfer, Luminescence Switching, and Quantum Yield

Nanorods of YPxV1-xO4:Ln3+ (Ln3+ = Dy3+, Eu3+, Sm3+) have been synthesized hydrothermally. The substitution of vanadium (V5+) by phosphorous (P5+) ions in YVO4 was confirmed by X-ray diffraction studies and also supported by Fourier transform infrared spectroscopy, transmission electron microscopy and photoluminescence (PL) studies. The energy transfer (ET) rate to the activator can be controlled either by activator concentration or by doping with P in the crystal. The ET is reduced by P doping due to the increase in separation between vanadium ions. This has been established from both steady state luminescence and decay studies. The controlled ET leads to the blue color emission from the vanadate (VO 43-) transition in YPxV1-xO 4 and generates a multicolored light emission even with single doping of the activator. Further, the color of emission can also be tuned by multiple doping of the activators. Interestingly, white light is obtained by doping with Dy3+ (1 at.%) and Sm3+ (0.75 at.%) in YP 0.8V0.2O4. The quantum yield of white light emission is found to be 25%. CIE chromaticity supports the tunability of the light and the white light emission. © 2014 The Royal Society of Chemistry.

Journal of Materials Chemistry C

Multicolor tuning and white light emission from lanthanide doped YPVO 4 nanorods: Energy transfer studies

Luminescence intensity of rare-earth doped materials can be varied depending on shape of particles, capping agent, and heat-treatment. This is related to the non-radiative rate possessed by the material. Here, we observed the high quenching of the luminescence intensity of Eu 3 doped GdPO 4 prepared in water (H 2O) medium. On the contrary, in ethylene glycol (EG) medium, it shows high luminescence. Luminescence intensity is recovered when Eu 3+ doped GdPO 4 nanorods prepared in H 2O medium is heated above 700 °C. This transforms hexagonal to monoclinic structure following the removal of water. Luminescence intensity is enhanced by changing the medium from H 2O to D 2O and also if core-shell formation occurs. Also, we found significant variation in bending and stretching vibrations of O-H and microstructure in this material prepared in H 2O and EG. Two types of O-H stretching frequencies are observed at 3450 and 3520 cm -1 in H 2O medium prepared sample which are assigned to the O-H having the hydrogen bonding (surface water) and the confined water, respectively. The formation of nanorods is due to the presence of water on the surface of particles or/and inside the pores of compound. The available water in the nanoparticles pores can be utilized for the efficient killing of mass cells tumor by generating reactive free radicals (H · and OH ·) through the application of laser near infrared (NIR) source and the subsequent irradiation of gamma ray. This proposed mechanism is quite different from the conventional treatment of mass cell/malignant tumor using gamma ray radiation. Sample is highly paramagnetic and it will be useful for magnetic resonance imaging contrast agent. © 2012 American Institute of Physics.

Journal of Applied Physics

Disappearance and recovery of luminescence in GdPO 4:Eu 3 nanorods: Propose to water/OH ̇ release under near infrared and gamma irradiations

Journal of Physics: Condensed Matter

Lanthanide 4f-level location in AVO4:Ln3+(A = La, Gd, Lu) crystals

Journal	AIP Conference Proceedings
Publisher	Author(s)
ISSN	0094243X
Open Access	0