在本研究中，我們探討了單一極性金屬接觸點於Ｐ型表層作為兩個電極之氮化鎵系列發光二極體的發光現象，並比較了Ｐ－Ｐ和Ｐ－Ｎ構型元件的電致發光光譜、電流－電壓特性和發光－電流特性。為了有效的分析其發光之原理，我們討論了背靠背二極體之電流-電壓關係。同時也探討了將逆向偏壓接面之等效成一個大阻值電阻之模型的限制。除此之外，透過對電流－電壓特性的一次、二次微分之分析模型技術，定量的分析了此Ｐ-Ｐ構型元件之等效電路，並計算不同元件尺寸、電極間隔、Ｐ型層厚度之等效串連電阻及等效並聯電阻。在此基礎上，我們提出了一個透過浮接基板自我調整電位分佈，而造成之大量漏電流流經背靠背二極體之接面的模型，並以此解釋此Ｐ－Ｐ構型發光元件的工作原理。透過將Ｐ－Ｐ構型發光元件串聯製作之交流驅動發光二極體，我們展示了此簡單單一極性金屬作為電極接點技術的發展潛力。由於只需要單一極性之金屬接觸點於元件之一側，此一技術不僅可以應用於氮化鎵光電元件非破壞性、便捷之電致發光光譜量測，也提供了大能隙半導體的新型元件結構可能性。除此之外，對於薄膜層狀半導體電性量測，例如霍爾量測，也需要注意本研究所提出的漏電路徑模型，是否會造成測量結果判讀的誤差。

In this piece of work, luminescence of GaN-based light emitting devices fabricated with single-polarity metal contacts both on the p-type top layer has been investigated. Direct comparisons of electroluminescence spectra, current-voltage and luminance-current characteristics between p-n and p-p configuration devices have been carried out. For a comprehensive analysis of the p-p configuration device, the current-voltage behavior of back-to-back diodes is discussed and the limitations to treat the reversed junction in the back-to-back diode model as a large series resistance is analyzed. Moreover, the equivalent circuit of the p-p configuration devices is established and quantitatively modeled by analyzing the current-voltage characteristics using the derivative methodology. With the aid of this derivative current-voltage (DIV) technique, effective parasitic shunt resistance and series resistance were calculated. Based on the analyses of current-voltage characteristics, the working principle involving with a self-adjusting potential which leads to the large leakage current though back-to-back junctions is proposed to explain the possible mechanism for the sustaining current required in current-controlled luminescence devices. An integrated alternating-current light emitting diode operated at 120 V is fabricated based on this simplified single-polarity metal contact technique to demonstrate the potential of this technique. Besides the application as a rapid and nondestructive electroluminescence assessment in GaN-based optoelectronic devices just with a simple need of using only single-polarity metal contact on one side, this technique may also shed lights on a new device structure for wide-bandgap optoelectronic devices or raises cautions about assessing results of Hall measurements on materials consisting of p/n junctions.

中文摘要 I
ABSTRACT II
CONTENTS IV
LIST OF FIGURES V
CHAPTER 1. INTRODUCTION 1
1-1. Overview 1
1-2. Goal of the Thesis Work 7
CHAPTER 2. BACKGROUND THEORY 9
2-1. Overview 9
2-2. Current-Voltage Behavior of Back-to-Back Diode 10
2-3. Norde Modified Current-Voltage plot 20
2-4. Derivative Current-Voltage (DIV) Method 21
2-5. Derivative Current-Voltage (DIV) Method for Back-to-Back Diodes 29
CHAPTER 3. EXPERIMENTAL SETUP 41
3-1. Device Structure and Fabrications 41
CHAPTER 4. RESULTS AND DISCUSSIONS 49
4-1. Transmission Electron Microscopy Analysis 49
4-2. The Electroluminescence Properties 52
4-3. The DIV Analysis of Current-Voltage Properties 55
4-4. Leakage Mechanism of p-p Configuration Devices 65
4-5. Fabrication of ACLED Based on p-p Configuration 78
CHAPTER 5. CONCLUSION 81
APPENDIX I. 83
APPENDIX II. 89
REFERENCE 91

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