Particle Size Effect on the Packaging Performance of YAG:Ce Phosphors in White LEDs

Abstract

The synthesis of cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor of different sizes with uniform size distribution was carried out using solid-state reaction followed by grinding and sieving method. The effect of particle size distribution of YAG:Ce phosphors on the photoluminescence (PL) properties was investigated. The results demonstrate that the uniform size distribution and particle size affects the packaging performance in white light emitting diode (LED) applications. The YAG:Ce phosphors with different particle sizes were packaged in white LEDs using different amounts of each phosphors in order to get similar efficiency as that of commercially available YAG:Ce phosphors. It was observed that minimum amount of phosphor material is required for smaller particle size for getting the similar efficiency as that exhibited by commercially available YAG:Ce phosphors. The results are particularly interesting in view of reducing the cost of current LEDs by lowering the amount of phosphors without compromising the efficiencies of final LED package. A systematic study of YAG:Ce phosphors on the packing performance in white LEDs is reported.

Monodispersed spherical YAG:Ce3+ phosphor particles by one-pot synthesis

“…These properties have advantages in manufacturing process as well as enhanced optical efficiency [8]. Therefore, uniform particle size distribution and controlling morphologies are very important factors in fabricating highly efficient LEDs [9]. It is well known that phosphors with small particle size have enhanced optical properties due to reduce back scattering in emitting.…”

Microwave-Induced Combustion Synthesis of Luminescent Aluminate Powders

“…This kind of powder cannot be reasonably dispersed in a suspension in order to design homogeneous luminescent films. Furthermore, as discussed in the introduction, a large particle size distribution is generally prejudicial to the efficiency of LED-based lighting devices (Huang et al 2009). …”

“…In this context, phosphor-converted light emitting diodes (LEDs) appear as the most interesting candidates to replace energy-greedy incandescent light bulbs and fluorescent lamps. Indeed, it is now a mature technology that can compete with the former ones, especially thanks to their long lifetime, low-power consumption, high energy efficiency and robustness (Höppe 2009;Huang et al 2009;Smet et al 2011). However, some drawbacks remain, such as the lack of high colour rendering devices.…”

“…Defects have also to be avoided because they act as luminescence shifters or quenchers. Furthermore, it has been proved in several recent studies that white LEDs using smaller particles size, with narrower grain size distribution, required a lower amount of phosphor to get similar efficiency than LEDs using bigger particles (Huang et al 2009;Jia et al 2007). It has been related to the reduction of internal light scattering when these nanoparticles are directly coated onto the LEDs surface at the front of this.…”

Measuring, simulating and optimizing current LED phosphor systems to enhance the visual quality of lighting

“…In this article, phosphor particle size in narrow particle size distribution YAG and LuAG phosphors were first considered to optimize the PC-LED's visual quality of lighting. The impact of YAG phosphor particle size on PC-LED light output [6][7][8] was reported in literature. However, these investigations were conducted on phosphors from different manufacturers hence it is difficult to compare them.…”