• N S KOKODE

Articles written in Bulletin of Materials Science

• Optical properties of rare earth-activated Ca$_3$(PO$_4$)$_2$:RE (RE = Eu$^{3+}$ and Dy$^{3+}$) phosphors prepared by wet chemical synthesis

Optical properties of rare earth-activated Ca$_3$(PO$_4$)$_2$:RE (RE = Eu$^{3+}$ and Dy$^{3+}$) phosphors obtained by wet chemical synthesis method, are reported in this paper. The phase confirmation of synthesized phosphor host is done by X-ray diffraction study. SEM images of the sample host reveal irregular morphology with collection of particles and porous nature. The crystal structure is not viewed with naked eyes, although particle size ranges from 2–5 micrometres. Photoluminescence characterization of Ca$_3$(PO$_4$)$_2$:Eu$^{3+}$ gives characteristic orange–red emission at wavelengths of 594, 613 and 617 nm upon near UV excitation at 397 nm attributed to ${}5$D$_0$ ${\rightarrow}$ ${}7$F$_1$, ${}7$F$_2$ transition of rare earth Eu$^{3+}$ ion. Whereas Ca$_3$(PO$_4$)$_2$:Dy$^{3+}$ gives blue–yellow emissions at wavelengths 483 and 574 nm due to near UV excitation at wavelength of 351 nm, which are corresponding to ${}4$F$_{9/2}$ ${\rightarrow}$ ${}6$H$_{15/2}$, ${}6$H$_{13/2}$ transitions of dopant ion Dy$^{3+}$. Colour coordinates from CIE diagram of 483 and 574 nm are obtained at (x = 0.0781, y = 0.1704) and (x = 0.471, y = 0.527) for the Ca$_3$(PO$_4$)$_2$:Dy$^{3+}$ phosphor. Whereas in the case of Ca$_3$(PO$_4$)$_2$:Eu$^{3+}$ for an emission wavelength of 613 nm, the colour coordinates are found to be (x = 0.674, y = 0.325). The presented optical investigation of phosphor displays that the reported phosphor can be a potential contender for ecofriendly solid-state lighting.

• # Bulletin of Materials Science

Volume 45, 2022
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Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020