Synthesis and Characterization of Ce-Doped Y3Al5O12(YAG:Ce) Nanopowders Used for Solid-State Lighting

Do Ngoc Chung,Nguyen Nang Dinh,Vo-Van Truong,Tran Thi Thao,Do Ngoc Hieu

doi:10.1155/2014/571920

Do Ngoc Chung, Nguyen Nang Dinh + Show 3 more

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https://doi.org/10.1155/2014/571920

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Abstract

Nano-Ce-doped Y3Al5O12(YAG:Ce) powders were synthesized by using a sol-gel low temperature combustion method, followed by thermal annealing. The annealing temperature for enriching nanoparticles was optimized and found to be 1000°C. The process for enriching uniform nanoparticles of YAG:Ce powder was carried out by using the nanosteam technique (NST). The nanoparticles obtained from this NST treatment had a size in the range of 9–20 nm. Measurements of the photoluminescence spectra of the dispersed YAG:Ce nanoparticles solutions showed a blue shift in the photoemission with a value of ca. 10 nm in the green region. WLEDs made from the blue LED chip coated with the nano-YAG:Ce + MEH-PPV composite epoxy exhibit white light with a broad band luminescent spectrum and a high color rending index (CRI). The photoluminescence spectra of the YAG:Ce nanoparticles showed a potential application of the prepared nanostructured YAG:Ce phosphor not only in energy-efficient solid-state lighting, but also in optoelectronic devices, including organic composite solar cells. In addition, it is suggested that NST can be applied for the enrichment of uniform inorganic nanoparticles.

Highlights

Research and applications of solid-state lighting (SSL) have grown exponentially in the world since the discovery of InGaN fabrication process by Nakamura et al [1]
We present the results on the process of the nanoparticles enrichment from the LTC-prepared YAG:Ce powder and characterization of the size distribution of nanoparticles by using a dynamic light scattering particle size analyzer combined with the nanosteam technique (NST) treatment
Nanopowder of YAG:Ce was collected from the column and reannealed at 450∘C for 2 h. This powder was further used for characterization and preparation of nanocomposites that were coated onto a blue LED chip to get the solid-state lighting lamp

Summary

Introduction

Research and applications of solid-state lighting (SSL) have grown exponentially in the world since the discovery of InGaN fabrication process by Nakamura et al [1]. Under blue light excitation of the LED chips, YAG:Ce phosphor emits a broad spectrum from 500 to 650 nm, due to the 5d-4f transition of Ce3+ ion [6] This is the reason why YAG:Ce phosphor has extensive application in WLEDs. There are many methods used for the preparation of the YAG powder with a high crystallinity, a large luminous power, and a small particle size, such as methods using solid-state reaction [7,8,9,10], coprecipitation, [11,12,13] and sol-gel process [14]. The crystalline structure, surface morphology, and photoluminescent properties of YAG:Ce powders and emission spectra of the WLEDs were studied

Experimental

Results and Discussion

Conclusion