均勻的電流分佈對高功率發光二極體之發光效率、穩定度及元件壽命具有高度的影響，由相關文獻可歸納出改善電流均勻性分佈的方法有：電極形狀、n-GaN厚度、電極阻抗及電流阻塞結構，其中理想化的電極形狀設計是提高發光效率最有效的方式。因此本論文主要的目的在於設計出不同的電極配置並搭配模擬分析，分別探討在相異的電極配置下，對Thin-GaN發光二極體光電特性的影響。 本論文之電極設計主要藉由改變電極圖形迴圈數、電極與晶粒邊緣相對距離及電流注入位置等條件，縮短電流橫向擴散距離，達到減少串聯電阻並增加電流均勻性之目的。在電極圖形迴圈數方面，因串聯電阻的減少，使多迴圈電極較單迴圈電極可降低約2%的順向偏壓，且均勻的電流分佈可增加了9%發光強度；而在電極與晶粒邊緣相對距離為1/4時，順向偏壓較相對距離為1/2的電極減少4%，發光強度則有11%的提升。由此可知，當增加電極迴圈數搭配縮短電極與晶粒邊緣之相對距離時，會得到較均勻的電流分佈表現。此外，比較實驗與模擬結果，在順向偏壓及發光強度上兩者變化趨勢相符；而電流密度與光強分佈，亦有類似的變化趨勢，結果表示數值模擬方法在預測順向偏壓與電流分佈均勻性上已具有可參考之價值。 High power LED chip performances are affected by the uniform current spreading on its lighting efficiency, stability, and device reliability. According to the literature review, methods which can improve the uniform current spreading are electrode shape, thickness of n-GaN, resistance of electrode, and current blocking layer. While designing an ideal electrode, the electrode pattern is the most efficient method to enhance the light efficiency. This thesis is trying to design different electrode patterns on LEDs and attached with the analyses of simulation to discuss the effect of electrical and optical performance by electrode design of Thin-GaN LED. This thesis is trying to change the electrode loops, the distance between electrode and chip edge, and current injected positions to shorten the distances of current sidelong spreading. It can reduce the series resistance and improve current spreading. On the electrode loops concern, the multiple loops can reduce forward voltage for 2 % than single loop because of the reducing of series resistance and enhance light output power on the uniform current spreading for 9 %. When the electrode is one-fourth far away from chip edge, the forward voltage reduces 4 % as the distance is one-second far away from chip edge and enhances the light output power for 11%. Based on these results, increasing the electrode loops attached with the distance of electrode and chip edge will show more uniform current spreading. In addition, comparing to the results of experiment and simulation, the trends are consistent on the forward voltage and light intensity. It also shows similar trends on the current density and light intensity distribution. The results represent that the method of simulation to predict the forward voltage and uniform current spreading are worth inferring.
