使用光學路徑探討金字塔微結構氮化鎵發光二極體之光萃取效率

Abstract

本論文中，我們研究的氮化鎵發光二極體，並根據金字塔型微結構所在的位置不同將其分為三種類型來研究。類型一，金字塔型微結構被建立在藍寶石基板的頂面之上；類型二，金字塔型微結構被建立在P-型氮化鎵的頂面之上；類型三，金字塔型微結構被同時建立在藍寶石基板和P-型氮化鎵的頂面之上。我用以上三種類型來探討微結構與出光效率的關係，發現類型三擁有最好的出光效率。此外，在我們的模擬中七條光子逃脫路徑伴隨著大量的光子逃脫量，因此這七條逃脫路徑可以預測最佳出光效率的金字塔微結構傾角。

We study three different gallium-nitride (GaN) based light emitting diode (LED) cases based on the different locations of the pyramid textures. In case 1, the pyramid texture is located on the sapphire top surface, in case 2, the pyramid texture is locate on the P-GaN top surface, while in case 3, the pyramid texture is located on both the sapphire and P-GaN top surfaces. We study the relationship between the light extraction efficiency (LEE) and angle of slant of the pyramid texture. The optimization of total LEE was highest for case 3 among the three cases. Moreover, the seven escape paths along which most of the escaped photon flux propagated were selected in a simulation of the LEDs. The seven escape paths were used to estimate the slant angle for the optimization of LEE and to precisely analyze the photon escape path.