Ranjoy Wangkhem
@nitmanipur.ac.in
DST INSPIRE Faculty, Department of Physics
National Institute of Technology Manipur
EDUCATION
Ph.D. in Physics (2022)
M.Sc. Physics (2015)
B.Sc. Physics (H) (2013)
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Materials Science, Electronic, Optical and Magnetic Materials, Instrumentation
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ranjoy Wangkhem, Kedukhro Khupfu, N. Yaiphaba, and N. Shanta Singh
Elsevier BV
Ranjoy Wangkhem, O. Shantajit Singh, and N. Shanta Singh
Springer Science and Business Media LLC
Ranjoy Wangkhem, N. Premananda Singh, and N. Shanta Singh
Elsevier BV
O. Shantajit Singh, Ranjoy Wangkhem, N. Yaiphaba, and N. Shanta Singh
Elsevier BV
O. Shantajit Singh, Ranjoy Wangkhem, N. Yaiphaba, Th. David Singh, and N. Shanta Singh
Elsevier BV
Ranjoy Wangkhem, Takhe Yaba, N. Shanta Singh, and R.S. Ningthoujam
Elsevier BV
O. Shantajit Singh, Ranjoy Wangkhem, and N. Shanta Singh
Elsevier BV
Takhe Yaba, Ranjoy Wangkhem, and N. Shanta Singh
Elsevier BV
Takhe Yaba, Ranjoy Wangkhem, and N. Shanta Singh
Springer Science and Business Media LLC
Ranjoy Wangkhem, N. Shanta Singh, N. Premananda Singh, S. Dorendrajit Singh, and L. Robindro Singh
Elsevier BV
Ranjoy Wangkhem, Takhe Yaba, N. Shanta Singh, and R. S. Ningthoujam
AIP Publishing
CaMoO4:Eu3+ (3 at. %)/Bi3+ (x at. %) nanophosphors were synthesized hydrothermally. All the samples can be excited by 280, 320, 393, and 464 nm (blue) wavelengths for generation of red color emission. Enhancement in 5D0 → 7F2 (615 nm) emission (f-f transition) of Eu3+ is observed when Bi3+ is incorporated in CaMoO4:Eu3+. This is due to the efficient energy transfer from Bi3+ to Eu3+ ions. Introduction of Bi3+ in the system does not lead to the change of emission wavelength of Eu3+. However, Bi3+ incorporation in the system induces a shift in Mo-O charge transfer band absorption from 295 to 270 nm. This may be due to the increase in electronegativity between Mo and O bond in the presence of Bi3+ leading to change in crystal field environment of Mo6+ in MoO42−. At the optimal concentration of Bi3+, an enhancement in emission by a factor of ∼10 and 4.2 in the respective excitation at 393 (7F0 → 5L6) and 464 nm (7F0 → 5D2) is observed. The energy transfer efficiency from Bi3+ to Eu3+ increases from 75% to 96%. The energy transfer is observed to occur mainly via dipole-dipole interactions. Maximum quantum yield value of 55% is observed from annealed CaMoO4:Eu3+ (3 at. %) when sensitized with Bi3+ (15 at. %) under 464 nm excitation. From Commission International de I'Eclairage chromaticity coordinates, the color (red) saturation is observed to be nearly 100%.CaMoO4:Eu3+ (3 at. %)/Bi3+ (x at. %) nanophosphors were synthesized hydrothermally. All the samples can be excited by 280, 320, 393, and 464 nm (blue) wavelengths for generation of red color emission. Enhancement in 5D0 → 7F2 (615 nm) emission (f-f transition) of Eu3+ is observed when Bi3+ is incorporated in CaMoO4:Eu3+. This is due to the efficient energy transfer from Bi3+ to Eu3+ ions. Introduction of Bi3+ in the system does not lead to the change of emission wavelength of Eu3+. However, Bi3+ incorporation in the system induces a shift in Mo-O charge transfer band absorption from 295 to 270 nm. This may be due to the increase in electronegativity between Mo and O bond in the presence of Bi3+ leading to change in crystal field environment of Mo6+ in MoO42−. At the optimal concentration of Bi3+, an enhancement in emission by a factor of ∼10 and 4.2 in the respective excitation at 393 (7F0 → 5L6) and 464 nm (7F0 → 5D2) is observed. The energy transfer efficiency from Bi3+ to Eu3+ increases from 75% to 96%...
N. Shanta Singh, Ranjoy Wangkhem, Takhe Yaba, Suman Devi, M. Niraj Luwang, N. Yaiphaba, H. Sylvia Devi, and Th. David Singh
Elsevier BV