Synthesis and luminescent characteristics of yellow emitting GdSr2AlO5:Ce3+ phosphor for blue light based white LED.

Abstract: A series of Ce3+ ions doped GdSr2AlO5 (GSA) phosphors were synthesized by a citric acid based sol–gel method. The X-ray diffraction patterns confirmed their tetragonal structure after the samples were annealed at 1300°C, and the scanning electron microscope image showed the closely packed particles. The excitation spectra revealed that the GSA phosphor effectively excited with blue light of 442nm due to the 4f1→5d1 transition and exhibited yellow emission corresponding to the 5d1→4f1 transition of Ce3+ ions. The optimum doping concentration of Ce3+ ions was 5mol% and the critical distance was calculated to be ~17Å. White LEDs were fabricated by combining blue LED (465nm) chip with Ce3+:GSA phosphor. The CIE chromaticity coordinates (0.34, 0.31) provide their emission potentiality in the white light region. [Copyright &y& Elsevier]