Associate Professor


School of Pure & Applied Physics
Mahatma Gandhi University
Kottayam-686 560,India


Phone: +91 9446316179

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M. Sc (Master of Science),  Cochin University of Science & Technology, Kerala, India

Ph. D (Doctor of Philosophy), School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam

  • Total Number of publications: 101
  • h-index : 16
  • Citation index-current: 922
  • Number of Ph. Ds Supervised: 6
  • Number of M.Phils Supervised: 11
  • No of conferences and symposia attended: 25
  • No of seminar/conference convened : 3
  • Projects Ongoing (co-investigator) : 0
  • Inspire / INCULCATE conducted with date: 1
  • No of students currently doing research: 6
  • The reviewer of international journals: 7

Membership of Professional/Academic bodies

  • Indian Laser Association
  • Association of Physics Teachers

Research Areas

Display device materials: Laser Spectroscopy, Photonics & Nonlinear optics, Glassy materials

The activities in this field include synthesis and characterization of selected phosphors for display applications.  Two types of systems have so far been investigated.  In the first class,Ferroelectric

Strontium Barium Niobate fine ceramic systems doped with different rare-earth ions were prepared and investigated for their structural and optical properties. We are also successful in sol-gel synthesis of different compositions of these materials in the nano-regime.  The other group of phosphor material investigated belongs to Sr 2 CeO 4 , a recently reported blue phosphor by the combinatorial materials synthesis technique.Currently, we are investigating the effect of different rare-earth ions on the structural and optical properties of this interesting group of materials.  These materials have been prepared in the nano regime using sol-gel synthesis using different chemical routes. The thin film preparation and characterization of these systems are in progress. The group has also synthesized Cd x Zn 1-x S quantum dot alloys through chemical method and investigated the luminescent and optical limiting properties.

Selected Publication

Specialization: Condensed Matter Physics, Spectroscopy
Course Offered : Classical Mechanics, Nuclear Physics, Optoelectronics, Research Methodology
Current Research interest : Photonic Materials, Rare earth doped Glasses, Phosphor Materials.

Selected Publication:

  •  Synthesis and luminescence characterization of Pr 3+ doped Sr 1.5 Ca 0.5 SiO 4 phosphor.Viji Vidyadharan, Kamal P. Mani, M.S. Sajna, Cyriac Joseph, N.V. Unnikrishnan,P.R. Biju. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 133 (2014) 767–772
  • Synthesis and luminescence characterization of Sr 0.5 Ca 0.5 TiO 3 :Sm 3+ phosphor.Viji Vidyadharan, Mohan P. Remya, Subhash Gopi, Sunil Thomas, Cyriac Joseph,N.V. Unnikrishnan, P.R. Biju. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 150 (2015) 419–429
  • Spectroscopic and photoluminescence characterization of Dy 3+ in Sr 0.5 Ca 0.5 TiO 3 phosphor. Viji Vidyadharan, E. Sreeja, Saritha K. Jose, Cyriac Joseph, N. V. Unnikrishnan,P. R. Biju. Luminescence: Journal of Biological and Chemical Luminescence 31 (2015) 202–209
  • Structural, optical and AC electrical properties of Ce 3+ -doped TiO 2 –SiO 2 matrices.Viji Vidyadharan, Prathibha Vasudevan, S. Karthika, Cyriac Joseph, N.V Unnikrishnan, P.R.Biju. Journal of Electronic Materials, Vol. 44, No. 8, (2015)
  • Luminescent characteristics of UV excited Sr 0.5 Ca 0.5 TiO 3 :Pr 3+ reddish orange phosphor.Viji Vidyadharan, Remya Mohan P, Cyriac Joseph, N.V. Unnikrishnan, P.R. Biju.Materials Chemistry and Physics 170 (2016) 38-43
  • Structural and optical characterization of Eu 3+ doped polymer-zirconia composites.Saritha K. Jose, Subash Gopi, Sanu Mathew Simon, Remya Mohan P., Cyriac Joseph, N.V.Unnikrishnan, P.R. Biju. Journal of Non-Crystalline Solids 452 (2016) 245–252
  • Judd–Ofelt analysis of Pr 3+ ions in Sr 1.5 Ca 0.5 SiO 4 and Sr 0.5 Ca 0.5 TiO 3 host matrices.Viji Vidyadharan, Subash Gopi, Remya Mohan P, Vinoy Thomas, Cyriac Joseph,N.V. Unnikrishnan, P.R. Biju. Optical Materials 51 (2016) 62–69
  • Dielectric properties of Sr 0.5 Ca 0.5 TiO 3 :xPr 3+ ceramics. Viji Vidyadharan, E. Sreeja, Santhosh Kumar A, Cyriac Joseph, N.V. Unnikrishnan,P.R. Biju. Ceramic International 43 (2017) 6268-6275.
  • Synthesis and luminescence characteristics of CaB 2 O 4 :Er 3+ ,Li + phosphor. Remya Mohan P, Subash Gopi, Viji Vidyadharan, Anns George, Cyriac Joseph,N.V. Unnikrishnan, P.R. Biju. Journal of Luminescence 187 (2017) 113–120
  • Judd–Ofelt analysis, structural and spectroscopic properties of sol–gel derived LaNbO 4 :Dy 3+ phosphors. P. Remya Mohan, Viji Vidyadharan, E. Sreeja, Cyriac Joseph, N. V. Unnikrishnan,P.R. Biju. Journal of Materials Science: Materials in Electronics 28 (2017)10250–10261
  • Luminescence properties and charge transfer mechanism of host sensitized Ba 2 CaWO 6 :Eu 3+ phosphor. Sreeja E, Subash Gopi, Viji Vidyadharan, Remya Mohan P, Cyriac Joseph,N.V. Unnikrishnan, P.R. Biju. Powder Technology (2017, Accepted manuscript)
  • Luminescence and phonon sideband analysis of Eu 3+ doped alkali fluoroborate glasses for red emission applications. Subash Gopi, Saritha K Jose, Anns George, N. V Unnikrishnan, Cyriac Joseph, P. R Biju. Journal of Materials Science: Materials in Electronics, (2017, Accepted manuscript)
  • Tunable green to red emission via Tb sensitized energy transfer in Tb/Eu co doped alkali fluoroborate glass. Subash Gopi, Saritha K. Jose, E. Sreeja, P. Manasa, N.V. Unnikrishnan, Cyriac Joseph, P.R. Biju. Journal of Luminescence, (2017, Accepted manuscript)