以二氧化鈦奈米粒子摻雜矽膠提升封裝後藍色發光二極體之光取出效率

Enhancement of Light Extraction Efficiency in GaN-Based Blue Light-Emitting Diodes by Doping TiO2 Nano-Particle in Encapsulation Silicone

王品超(Pin-Chao Wang)

指導教授 ： 林俊良

崑山科技大學/工程學院/光電工程研究所/碩士(2010年)

摘要

半導體白色發光二極體(LEDs)因具有節能、環保等等諸多優點，被視為是未來固態照明的核心，提高LED的光取出效率，則被認為是目前的主要關鍵。提高封裝膠體的折射係數，被視為是提高LED光取出效率的有效方法之一。由於二氧化鈦(TiO2)具有較高的折射係數(n=2.8)，因此在本論文中，我們將TiO2奈米粒子摻入封裝LED的矽膠中，提高封裝矽膠的整體平均折射係數，而混合後折射率量測為1.55，以提高LED元件之光取出效率。
在選擇區域中，將二氧化鈦(TiO2)奈米粒子混入矽膠，並應用在藍色發光二極體(LED)之封裝，藉由提高矽膠之光折射係數，以增加藍光LED之光取出效率。TiO2摻入矽膠應用於封裝的位置配置，包括有均勻摻入所有封裝矽膠中、僅覆蓋於晶片周圍、及遠離晶片配至等三種方式。結果發現：當TiO2奈米粒子佔矽膠之重量百分率為0.01 %，且僅覆蓋於晶片周圍，將可讓藍光LED獲得最高的光取出效率。
連續點亮1500小時做壽命測試，我們發現摻雜入矽膠之TiO2奈米粒子與未摻雜，都有相同的電特性。而封裝矽膠中摻入合適比例的TiO2奈米粒子，可提升LED元件壽命。

關鍵字

二氧化鈦 ； 發光二極體

並列摘要

Semiconductor white light-emitting diodes (LEDs) were regarded as the nucleus of solid-state lighting in the near future, because of energy-saving, environment-friendly and many other advantages; the enhancement in light extraction efficiency of LEDs was considered to be the critical issue at present. Increasing the refractive index of encapsulating gel for package was considered as one of the effective ways to enhance the light extraction efficiency of LEDs. Because the titanium dioxide (TiO2) has high refractive index (n=2.8), therefore, in this thesis, we have doped the TiO2 nano-particles to the silicone of encapsulating gel to increase the overall refractive index of packaging silicone. The refractive index measurement is 1.55, and the light extraction efficiency of LEDs was enhanced.
TiO2 nano-particles were selected doping in part of the filled silicone for encapsulation of GaN-based blue light-emitting diode (LED). The refractive index of silicone was increased by mixing TiO2 nano-particles, and the light extraction efficiency of GaN-based blue LEDs was also increased. Optical characteristics of the GaN-based blue LEDs packaged in three modes of TiO2 nano-particles doping in silicone, including uniform, around LED chip only, and far from LED chip respectively were compared with conventional blue LEDs. The weight percentage of TiO2 nano-particles doping in silicone is 0.01%. The blue LED, with TiO2 nano-particles doping around LED chip only, has the highest.
Almost the same electrical characteristics were found for LEDs with/without TiO2 doped in silicone after 1500 hours continued life test.

並列關鍵字

TiO2 ； LED

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