高均勻性白光發光二極體

High Uniformity of Emission by ZrO2 Nano-particles for White LEDs

陳國儒(Kuo-Ju Chen) ； 陳信助(Hsin-Chu Chen) ； 蔡昕翰(Hsin-Han Tsai) ； 簡士軒(Shih-Hsuan Chien) ； 施閔雄(Min-Hsiung Shih) ； 林建中(Chien-Chung Lin) ； 郭浩中(Hao-Chung Kuo)

《光學工程》 122期 (2013/07) Pp. 7-11

摘要

在此研究中，我們利用氧化鋯奈米粒子發展高效率與高均勻性的白光發光二極體，透過噴塗高散射性氧化鋯奈米粒子於封裝體表面，藉此可增加光的散射特性，提高藍光在大角度的強度以改善變角度色溫的分布。此外，由於氧化鋯奈米粒子層的折射率介於空氣與螢光粉之間，因此可以達到漸變折射率的效果，進而提升其光萃取效率，以增進發光效率。在此新穎結構中，在大角度與垂直方向的色溫差異可以從1000K減少至420K，可有效的改善黃圈現象，並且由於前述的漸變折射率效果，其發光效率也可提高2.25%。故利用噴塗氧化鋯奈米粒子於封裝體表面的結構中不但可改善變角度的色溫均勻性，也可增加發光二極體的發光效率。

關鍵字

白光發光二極體 ； 氧化鋯奈米粒子 ； 封裝

並列摘要

In this study, high luminous efficiency and superior uniformity of angular-dependent correlated color temperature (CCT) white light-emitting diodes have been investigated by ZrO2 nano-particales in remote phosphor structure. By adding the ZrO2 nano-particles with silicone onto the surface of the phosphor layer, the capability of light scattering could be enhanced. Especially, the intensity of blue light at large angles was increased and the CCT deviations could be reduced. Besides, the luminous flux was improved due to the ZrO2 nano-particles with silicone provides a suitable refractive index between air and phosphor layers. This novel structure reduces angular-dependent CCT deviations from 1000K to 420K in range of -70 to 70 degrees. Meanwhile, the enhancement of lumen flux was increased by 2.25% at driving current 120mA, compared to conventional remote phosphor structure without ZrO2 nano-particales. Consequently, the ZrO2 nano-particales in remote phosphor structure could not only improved the uniformity of lighting but also increase the light output.

並列關鍵字

Light-emitting diodes ； ZrO2 nano-particales ； Package