應用奈米柱陣列與十二重準光子晶體之氮化銦鎵垂直式發光二極體

Abstract

在此論文中，成功展現應用奈米柱陣列結構及十二重準光子晶體製作在垂直式結構氮化銦鎵發光二極體的元件，並研究其特性及效果。 高深寬比的奈米柱陣列氮化銦鎵發光二極體。奈米柱陣列是藉由silica奈米小球作蝕刻遮罩，再使用ICP-RIE蝕刻而成。與沒有製作奈米柱陣列的垂直式發光二極體比較，光強度輸出增加了40%，且遠場光場的視角減少了20度，光也更向垂直表面方向集中。 另一方面，我們使用奈米壓印技術製作十二重準子晶體垂直式發光二極體，在20mA注入電流下，具有準光子晶體的垂直式發光二極，與沒有準光子晶體的元件相比，發光強度有78%的增益。有製作與沒有製作十二重光子晶體元件的光電轉換效率(WPE)分別是31%及52%。在遠場光場量測上，因為準光子晶體的導光效果，光束能有較小的發散情況，在垂直表面的方向更加集中，增加亮度且光場集中有助於聚光型光源的發展。

In the paper, we successfully demonstrated the InGaN/GaN vertical-injection LEDs with high aspect ratio nanorod array and the vertical-injection LEDs with 12-fold quasi-photonic crystal. We fabricated the vertical-injection LEDs with high aspect ratio nanorod array to improve the extraction efficiency and beam shaping. The nanorod array are patterned by self-assembled silica spheres, followed by inductively coupled-plasma reactive ion etching. The light output power of the vertical-injection LED with nanorod array is enhanced by 40%, compared to a conventional vertical-injection LED. The enhancement is mainly along the surface normal direction, within a view angle of 20 degree. Also, we fabricated and presented the GaN-based vertical-injection LEDs with 12-fold photonic quasi-crystal by nano-imprint lithography. At a driving current of 20mA, the light output enhancement of our vertical-injection LEDs with 12-fold PQC is 78% when compared with the output power of vertical-injection LED without PQC structure. Moreover, the wall plug efficiency of vertical-injection with and without 12-fold PQC are 52% and 31%, respectively. In addition, the corresponding light radiation pattern shows narrower beam shape due to the strong guided light extraction effect by the formed PQC structure in vertical direction. The light enhancement and beam shaping can use for the application of downlight and develop the solid state lightings.