ISNOG 2014, 19th International Symposium on Non-Oxide and New Optical Glasses, Aug. 24-28th, 2014, Jeju, KOREA

P1-4104-1021

Wavelength conversion material “Phosphor-glass composites” for high powersolid-state lighting
Tamio Ando, Tadahito Furuyama, Shunsuke Fujita, Masahiko Ohji
Nippon Electric Glass Co., Ltd., 7-1, Seiran 2-Chome, Otsu-shi, Shiga 520-8639 Japan,
tmando@neg.co.jp㪉㪅㪌㪈㪅㪇㪌

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Phosphor converted-Light Emitting Diodes / Laser Diodes (pc-LEDs/LDs) have been attracting muchattention as solid-state lighting devices. Most of the common pc-LEDs/LDs consist of Ce doped YAG
phosphor sealed in resin matrix and a blue-LED/LD for exciting light source. However, the resin matrix tends
to be deteriorated by heat arising from the high power of blue LED/LD. [1,2] This deterioration results inundesirable color changes and deformations of it, therefore lifetime of pc-LEDs/LDs might become short. To
solve these problems, we have developed a wavelength conversion material ‘Phosphor-Glass Composites’ inwhich phosphors are dispersed homogeneously.
The phosphor-glass composites were obtained by vitrifying mixtures of B2O3-SiO2 system glass powder andcommercial phosphors such as YAG, La3Si6N11:Ce (LSN) and -SiAlON. In the result of highly accelerated
stress test (Fig. 1.), the phosphor-glass composite shows higher weather resistance than conventional
phosphor-resin composite. The relative luminous flux didn’t change at all even if the sample was exposed
under a condition of 121°C, 95% RH and 2atm for 300h. The phosphor-glass composites provide anotherfeature that the variation in emission color is extremely small because of homogeneous dispersion of thephosphor in glass matrix and precise dimensional control in process. These phosphor-glass composites showhigh fluorescence intensity more than double, when appropriate blue band-pass filter is coated on the incident
surface of the exciting blue light source (Fig. 2.). The band pass filter consists of dielectric multi-layer.
As outputs of pc-LEDs/LDs increase, high weather resistance and heat resistance are required in wavelength
conversion materials. Phosphor-glass composites, which have high weather resistance and heat resistance, areexpected as a wavelength conversion material for high power solid-state lighting. Moreover, a small variationin emission color would help to precise optical designs of solid-state lighting devices㪈㪅㪇㪇㪇㪅㪐㪌㪧㪿㫆㫊㫇㪿㫆㫉㪄㪾㫃㪸㫊㫊㩷㪺㫆㫄㫇㫆㫊㫀㫋㪼㪧㪿㫆㫊㫇㪿㫆㫉㪄㫉㪼㫊㫀㫅㩷㪺㫆㫄㫇㫆㫊㫀㫋㪼

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Fig. 1. The change of total luminous flux during thehighly accelerated stress test under the conditions of121°C, 95% RH and 2 atm. (Phosphor: LSN)㪧㪿㫆㫊㫇㪿㫆㫉㪄㪾㫃㪸㫊㫊㩷㪺㫆㫄㫇㫆㫊㫀㫋㪼㪉㪅㪇㪧㪿㫆㫊㫇㪿㫆㫉㪄㪾㫃㪸㫊㫊㩷㪺㫆㫄㫇㫆㫊㫀㫋㪼㪂㩷㪙㪸㫅㪻㩷㫇㪸㫊㫊㩷㪽㫀㫃㫋㪼㫉㪈㪅㪌㪈㪅㪇㪇㪅㪌㪇㪅㪇㪋㪇㪇㪌㪇㪇㪍㪇㪇㪎㪇㪇㪮㪸㫍㪼㫃㪼㫅㪾㫋㪿㩷㩿㫅㫄㪀㪏㪇㪇

Fig. 2. Emission intensity of each sample.

References[1] H. Luo, J. K. Kim, E. F. Schubert, J. Cho, C. Sone, and Y. Park , “Analysis of high-power packages for phosphor-based white lightemitting diodes”, Appl. Phys. Lett. 86, 243505 (2005).
[2] S. I. Chan, W. S. Hong, K. T. Kim, Y. G. Yoon, J. H. Han and J. S. Jang, “Accelerated life test of high power white light emitting
diodes based on package failure mechanisms”, Microelectronics Reliability 51, 1806 (2011).

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