Structural and luminescence properties of yellow Y3Al5012:Ce3+ thin film phosphors prepared by Pulsed Laser Deposition

Abstract

Recently, by combining a blue indium gallium nitride (InGaN) light emitting diodes (LED) with yellow Ce-doped Y3Al5O12 (YAG) phosphore, different groups have successfully demonstrated white LEDs. The production of white light was made possible by the phosphore conversion from the LED to emission of a longer wavelength. The yellow emitting phosphore converts a major fraction of the blue excitation light from the LED chip into yellow light, and when both combined white light is produce. Bando et al. and Muller-Mach et el. have incorporated a phosphore/epoxy hybrid with a reflector cup containing a LED chip for phosphore conversion. The phosphore particles are randomly oriented and interdispersed in the cured epoxy. One of the bottleneck problems of the phosphore/epoxy hybrid system is the difficulty of achieving uniform emission of white light from the LED. In order to overcome the challenges of using mixtures of phosphore powders and epoxies thin film phosphore has been used. In this study, YAG phosphore thin films were prepared by pulsed laser deposition (PLD), and the effects of the PLD process parameters on the structural and luminescent properties of YAG thin films were investigated.