I am Dr. Koramala Naveen Kumar working as Postdoctoral Fellow in Department of Physics, Yeungnam University, South Korea. I worked as Research Professor (Assistant Professor), Department of Chemistry, Yeungnam University, South Korea for one year. I have been awarded the Ph.D degree in June 2015 from Sri Venkateswara University, Tirupati. My PhD thesis entitled “Studies on Magnetic, Electrical and Energy Transfer Based Photoluminescence Properties of Certain Transition Metal and Rare Earth Ions Doped PEO+PVP Blended Polymer Films for Electrochemical and Display Device Applications” under the guidance of Prof. Y.C. Ratnakaram. Besides my Ph.D. work, I have learned more on Nanomaterials, Glasses, Glass-Ceramics, Blended Polymers Films and Polymer Nanocomposites for optoelectronic, solid-state electrochemical and Electrochromic device applications. I have expertised knowledge in the field of analyzing the Optical absorption, Photoluminescence, EPR, NMR, VSM, AFM, HR-TEM, FESEM, XPS, FTIR, XRD, RAMAN, TG/DTA and Electrical properties. I have 6 years of teaching experience in the field of PG and UG studies in university level. I have published 30 papers in national and international reputed journals.
Dr. Koramala Naveen Kumar
3rd Clean Energy Priority Research Center(CEPRC) Workshop
June 21(Wed.), 2017
International Conference on Molecular Spectroscopy (ICMS 2017)
8, 9 & 10 December 2017
UPCOMING EVENTS
Fourth International Conference on Nanostructured Materials and Nanocomposites (ICNM 2017)
10-12 February 2017
MY LATEST RESEARCH
we have observed the remarkable emission features in co-doped Eu3+ (14 mol %) + Dy3+ (1, 2, 3 and 4 mol %) CLZO phosphors than singly doped Eu3+ (14 mol %): CLZO phosphor. Appreciable enhancement has been observed in emission intensities pertaining to Eu3+ ions by co-doping with Dy3+ ions in various concentrations. It is clearly noticed that the red emission intensity of 5D0→7F2 becomes strong in co-doped phosphors than the singly doped phosphor. This might be due to possible energy transfer from Dy3+ to Eu3+ ions in the co-doped CLZO phosphor [25]. In this co-doped system, the Dy3+ ions acting as sensitizers and Eu3+ ions acting as an activator ion. The red emission is found to be increased by increasing the Dy3+ ion concentration in the co-doped CLZO phosphor system. The predominant emission intensity has been observed at 2 mol % of Dy3+ ions consisted co-doped CLZO phosphor.
A bright novel red emission was obtained from Eu3+: CaLa2ZnO5 (CLZO) Phosphors under visible excitation. We have successfully synthesized Eu3+: CLZO Phosphors by the solid state reaction method. The phase formation and surface morphological studies were analyzed by X-ray diffraction and Field emission scanning electron microscopy respectively. Thermal analysis was done by TG/DTA. Photoluminescence spectral profiles reveal that the strong red emission has been noticed at 626 nm (5D0→7F2) from the Eu3+: CLZO Phosphors under the excitation of 467 nm. The emission and excitation spectral profiles were systematically analyzed and their bands were assigned with corresponding electronic transitions. Upon increasing the Eu3+ concentration, the photoluminescence performance has also been increased remarkably. The optimized concentration of the Eu3+ was noticed at 14 mol%. Upon co-doping with Dy3+ ions to Eu3+: CLZO Phosphors, the red emission pertaining to Eu3+ was appreciably enhanced through energy transfer form Dy3+ to Eu3+ ions. The energy transfer mechanism was substantiated by several fluorescent methods. The prominent red emission of the Dy3+/Eu3+: CLZO Phosphors under blue excitation which suggests that these phosphor materials could be promising candidates for red luminescent optical devices.
Key words: Phosphors, Red emission, Energy transfer.