A New Green Phosphor Using Solid-Solution and Their Structural and Optical Properties

Abstract

Garnet structure (cubic, space group Ia-3d) is recognized as highly stable and efficient host for white solid state lighting application. However, yellow Y3Al5O12:Ce3+ phosphor is associated with patent infringement while a replacement of yttrium with lutetium of form a similar structure Lu3Al5O12:Ce3+ (LuAG:Ce3+) phosphor would raise the cost of the LED device. The solid-solution design is an efficient route to develop new phosphors with various compositions. The commonly used solid-solution design method concentrates on the cation/anion substitution. The benefits vary from the color tuning of the peaking emission, to improved structural rigidity or chemical stability.(1) Garnet structure which accommodates wide variety of cations can be chosen as a template for such solid solutions. In this study, we report a new green-emitting phosphor, the Ce3+-doped garnet, which has better luminescence properties than the commercial LuAG:Ce3+phosphors. The influence of expanding substituted site by solid-solution and the change of photoluminescence intensity have been explored, and established their correlation. By the fabrication of white laser diodes, we explored its potential suitability in white laser diodes applications. This suggests that the phosphor displays great potential for application in white light generation using blue laser diodes. 1. W. B. Im, N. George, J. Kurzman, S. Brinkley, A. Mikhailovsky, J. Hu, B. F. Chmelka, S. P. DenBaars and R. Seshadri, Advanced Materials, 23, 2300 (2011). Figure 1. Photoluminescence excitation spectra and emission spectra of optimized sample by solid-solution and commercial LuAG:Ce3+phosphor at room temperature. Figure 1