Synthesis and luminescence properties of Sm3+ doped CaTiO3 nanophosphor for application in white LED under NUV excitation.
CaTiO3:Sm(3+) (1-11 mol%) nanophosphors were successfully synthesized by a low temperature solution combustion method [LCS]. The structural and morphological properties of the phosphors were studied by using Powder X-ray diffractometer (PXRD), Fourier transform infrared (FTIR), X-ray photo electron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscopy (TEM). TEM studies indicate that the size of the phosphor is ∼20-35 nm. Photoluminescence (PL) properties of Sm(3+) (1-11 mol%) doped CaTiO3 for NUV excitation (407 nm) was studied in order to investigate the possibility of its use in White light emitting diode (WLED) applications. The emission spectra consists of intra 4f transitions of Sm(3+), such as (4)G5/2→(6)H5/2 (561 nm), (4)G5/2→(6)H7/2 (601-611 nm), (4)G5/2→(6)H9/2 (648 nm) and (4)G5/2→(6)H11/2 (703 nm) respectively. Further, the emission at 601-611 nm show strong orange-red emission and can be applied to the orange-red emission of phosphor for the application for near ultra violet (NUV) excitation. Thermoluminescence (TL) of the samples irradiated with gamma source in the dose range 100-500 Gy was recorded at a heating rate of 5°Cs(-1). Two well resolved glow peaks at 164°C and 214°C along with shouldered peak at 186°C were recorded. TL intensity increases up to 300 Gy and thereafter, it decreases with further increase of dose. The kinetic parameters namely activation energy (E), frequency factor (s) and order of kinetics were estimated and results were discussed in detail.
Jawaharlal Nehru Technological University, Anantapur 515002, A.P., India; Department of Physics, VV Puram College of Science, Bangalore 560 004, India.
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Shivaram
Prof. CNR Rao, Centre for Advanced Materials, Tumkur University, Tumkur 572 103, India. Electronic address: bhushanvlc@gmail.com.
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Nagabhushana
Chhattisgarh Swami Vivekanand Technical University, Bhilai (CG)-493441, India.
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Sharma
Research Center, Department of Physics, East West Institute of Technology, Bangalore 560 091, India. Electronic address: scphysics@gmail.com.
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Prashantha
Chhattisgarh Swami Vivekanand Technical University, Bhilai (CG)-493441, India; Department of Physics, B.M.S. Institute of Technology, Bangalore 560 064, India.
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Daruka Prasad
Chhattisgarh Swami Vivekanand Technical University, Bhilai (CG)-493441, India; Department of Physics, B.M.S. Institute of Technology, Bangalore 560 064, India.
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Dhananjaya
Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
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Hari Krishna
Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
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Nagabhushana
Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India.
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Shivakumara
CSIR-National Aerospace Laboratories, Bangalore 560 017, India.
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Chakradhar
D017610:Calcium Compounds / Q000737:chemistry*; D049449:Luminescence; D019216:Metals, Heavy / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012493:Samarium / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D017610:Calcium Compounds; D019216:Metals, Heavy; D010087:Oxides; C059910:perovskite; D012493:Samarium; D014025:Titanium
Nanophosphor; Photoluminescence; SEM; TEM; Thermoluminescence; XRD