Structural and spectral investigation of terbium molybdate nanophosphor.
Terbium molybdate nanophosphors were synthesized through a facile sol-gel route. The structure of the phosphors was characterized by X-ray diffraction, Raman spectra and Fourier transform infrared spectroscopy analysis. The X-ray diffraction studies revealed that the structure of the nanophosphor gradually changes from monoclinic to orthorhombic phase as heated from 700 to 900 °C. High resolution transmission electron microscopy, SAED and EDS were also employed to characterize the size, crystallinity and composition of the samples. Detailed spectroscopic investigations were carried out by Judd-Ofelt analysis based on UV-Visible-NIR absorption and emission spectra. The luminescence spectra suggest that phosphors with orthorhombic structure have better luminescence properties than the monoclinic structure. The phosphors showed intense green emission under near-UV excitation due to the energy transfer from the host lattice to Tb(3+) ions. The CIE coordinates suggest enhanced color purity for green emission and short fluorescence decay values proposes the suitability for LED applications. These phosphors can be applied as promising candidates for blue and near-UV excited WLEDs.
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India.
Kamal P
KP
Mani
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India.
G
G
Vimal
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India.
P R
PR
Biju
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India. Electronic address: cyriacmgu@gmail.com.
Cyriac
C
Joseph
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India.
N V
NV
Unnikrishnan
School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560, India.
M A
MA
Ittyachen
Energy transfer; Judd–Ofelt analysis; Luminescence; Nanophosphor; Terbium molybdate