局部表面電漿子共振提升發光材料轉換效率應用於白色發光二極體之研究

Abstract

近年來電漿子光學已經成為新興研究領域，奈米級的金屬粒子獨特的光學特性被運用到各種光電元件上。由於藍光二極體的效率提升，螢光粉轉換（Phosphor-converted）白色發光二極體藉由藍光二極體激發無機發光材料（Inorganic luminescent materials）或稱為螢光粉（Phosphor）而形成白光，具有高效率、低能耗的優勢，所以被廣泛用於照明與背光的應用上。不過，由於螢光粉摻雜的稀土元素離子吸收藍光效率低，螢光粉轉換的白光二極體需要高比例的用量才能形成白光。

因此，本研究探討不同型態和不同濃度的銀奈米粒子對螢光粉的發光強度的影響。從結果發現在不同型態的銀奈米粒子有一優化點的濃度，可以有效的增強發光強度。由於銀奈米粒子產生的極化效應，有效的吸收藍光並轉換成綠光，使得綠光的發光強度上升13.5%。同時，在相同的色度座標下，螢光粉的使用量可以減少30％，而色度座標也從（0.214, 0.202）偏移到（0.235, 0.253）。Plasmonics has been becoming emerged research topic area in recent years. Plasmonics is applicated in different kinds of electro-optic devices due to unique optical properties of metallic nanoparticles. As result of efficiency improvement of blue light emitting diode, phosphor-converted white light emitting diode is produced by blue light emitting diode pumping inorganic luminescent materials. Owing to phosphor-converted white light emitting diode with high efficiency and low energy consumption. It is widely applicated in solid state lighting and backlight applications. However, dopped rare earth ions of phosphor has low efficiency in blue light absorption, phosphor-converted white light emitting diode requires considerably high percentage usage to form white light.

Therefore, this research is to investigate the influence of emission intensity on different types and different concentration of silver nanoparticles. From the results, the optimized point of concentration on different types of silver nanoparticles is found can efficiently enhance emission intensity. As result of polarizability produced by silver nanoparticles which can efficiently absorb blue light to convert green light, the emission intensity of green light enhanced by 13.5％. Meanwhile, in the same chromaticity coordinate, the usage of phosphor reduced by 30％, chromaticity coordinate also shifts from (0.214, 0.202) to (0.235, 0.253).