Effects of local structure of Ce(3+) ions on luminescent properties of Y3Al5O12:Ce nanoparticles.

Xiaowu He,Ronghai Yu,Xiaofang Liu,Kaili Yu,Min Zeng,Rongfeng Li,Bai Yang

doi:10.1038/srep22238

Abstract

Ce3+-doped yttrium aluminum garnet (YAG:Ce) nanocrystals were successfully synthesized via a facile sol-gel method. Multiple characterization techniques were employed to study the structure, morphology, composition and photoluminescence properties of YAG:Ce nanophosphors. The YAG:Ce0.0055 sintered at 1030 °C exhibited a typical 5d1-4f1 emission band with the maximum peak located at 525 nm, and owned a short fluorescence lifetime τ1 (~28 ns) and a long fluorescence lifetime τ2 (~94 ns). Calcination temperature and Ce3+ doping concentration have significant effects on the photoluminescence properties of the YAG:Ce nanophosphors. The emission intensity was enhanced as the calcination temperature increased from 830 to 1030 °C, but decreased dramatically with the increase of Ce3+ doping concentration from 0.55 to 5.50 at.% due to the concentration quenching. By optimizing the synthesized condition, the strongest photoluminescence emission intensity was achieved at 1030 °C with Ce3+ concentration of 0.55 at.%.

Highlights

The energy-efficient white light-emitting diode (WLED) has been widely applied as a solid-state optical source in various fields such as general lighting, car lighting backlighting sources, apparatus display screen and so on[1,2,3,4,5,6]
The crystallization temperature of yttrium aluminum garnet (YAG):Ce phosphors synthesized via sol-gel method is probably in the range of 830–900 °C
Nanocrystalline YAG:Ce phosphors with good dispersity were successfully prepared by sol-gel method

Summary

Introduction

The energy-efficient white light-emitting diode (WLED) has been widely applied as a solid-state optical source in various fields such as general lighting, car lighting backlighting sources, apparatus display screen and so on[1,2,3,4,5,6]. In order to overcome the above shortcomings, wet-chemical synthetic approaches have been developed for fabricating pure and homogeneous YAG:Ce phosphors He et al.[15,16] obtained YAG:Ce phosphors by spray pyrolysis method and could randomly control the grain size and composition of product particles with nano/microsphere morphology. The participation of 5d energy levels makes the transitions be sensitive to the crystal field environment and the site symmetry of the host lattice, i.e. local structure of CeY substitution Both of the emission intensity and wavelength depend on the local structure and distribution of the CeY in YAG:Ce phosphors[20,21]. A series of YAG:Ce nanocrystalline phosphors were prepared by sol-gel method[25] in terms of its advantages of uniform distribution of Ce3+ ions, fast reaction rate and low calcination temperature. We systematically clarified the intrinsic relationship among composition, structure and property

Methods

Results

Conclusion