Enhanced White Light Emission And Energy Transfer Studies Of Dy3+/Ce3+ Co-doped YAl3(BO3)4 Phosphors For White Light Emitting Diodes

G.V. Lokeswara Reddy1, L. Rama Moorthy1,2, T. Chengaiah1, B.C. Jamalaiah1,3*

1Department of Physics, Sri Venkateswara University, Tirupati 517 502, India

2Department of Physics, Chadalawada Venkata Subbaiah Engineering College, Tirupati 517 506, India

3Department of Materials and Ceramics Engineering, CICECO, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal

Adv. Mater. Lett., 2013, 4 (11), pp 841-848

DOI: 10.5185/amlett.2013. 3453

Publication Date (Web): Nov 02, 2013

E-mail: bcjamal@hotmail.com

Abstract


We reported the structure, photoluminescence and energy transfer studies of Dy3+/Ce3+ co-doped YAl3(BO3)4 (YAB) phosphors prepared by solid-state reaction method at 1200oC/3h. Upon 273 nm UV excitation, the YAB:Ce3+ phosphor exhibits a sharp emission band with peak maximum at 380 nm related to the parity and spin allowed Ce3+:5d → 4f transition. When excited with 352 nm, the broad emission band of Ce3+ contains two components at 390 and 417 nm due to the electric dipole transitions from 5d excited state to the two splitting ground 2F5/2,7/2 states, respectively. The incorporation of Ce3+ enhances the luminescence intensity of Dy3+ due to efficient energy transfer from Ce3+ to Dy3+. The emission spectra of Dy3+/Ce3+ co-doped phosphors under 273 nm excitation display the Dy3+:4F9/26H15/2,13/2,11/2 and the Ce3+:5d → 4f transitions. The emission colour can be tuned from blue-to-white as a function of Ce3+ concentration and/or excitation wavelength. Colour perception has been analyzed by evaluating the Commission International de I’Eclairagein (CIE) chromaticity coordinates. The YAB:Dy3+/Ce3+ phosphors can be significant for current generation UV excited white light emitting diodes.

Keywords

Phosphors, white light emission, solid state reaction, optical properties, luminescence.

Upcoming Congress

Knowledge Experience at Sea TM