具有不同界面層之氮化銦鎵/氮化鎵多重量子井及氧化鋅奈米結構之穿透式電子顯微術分析研究

Transmission Electron Microscopy Studies of InGaN/GaN Multiple Quantum Wells with Different Interfacial Layers and Zinc Oxide Nano-structures

吳政珉(Cheng-Ming Wu)

指導教授 ： 楊志忠

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.10059

摘要

本研究中，我們比較了四片具有不同界面層的氮化銦鎵/氮化鎵多重量子井（量子井無摻雜及矽掺雜於位障層）樣品的奈米結構和光學特性。在兩個具有氮化銦的界面層置於量子井及位障層之間的樣品中，其量子井的界面品質和發光效率都獲得改善，特別是在沒有矽摻雜的氮化銦界面層的樣品中，效果特別明顯。在另一個具有矽掺雜的氮化銦鎵界面層樣品中，因有此界面層，量子井寬度事實上變大，其內有類似量子點的結構和強烈的載子侷限現象，由此我們也觀察到相當高的螢光發光效率和相當強的激發螢光強度。和上述的樣品比較，常用的量子井樣品表現出最低的螢光發光效率，最低螢光發光光子能量和最弱的激發螢光強度。換句話說，加入氮化銦或氮化銦鎵界面層的確能改善光學特性。此外，我們還研究了五種氧化鋅奈米結構樣品（包括薄膜，牆狀和管狀）的奈米結構。在兩個薄膜樣品中，X光繞射結果顯示不同的長晶溫度會造成氧化鋅薄膜和基板間不同的磊晶關係。從牆狀氧化鋅的穿透式電子顯微鏡影像和繞射圖案中，我們可以證實牆狀及管狀結構內每個樹枝狀物都是具有相同方向的單晶。

關鍵字

量子井 ； 氮化鎵 ； 穿透式電子顯微術 ； 氧化鋅

並列摘要

In this research, we compare four InGaN/GaN multiple quantum-well (QW) samples (un-doped wells and silicon-doped barriers) of different interfacial layers in nanostructures and optical property. In two of the samples, InN interfacial layers are placed between wells and barriers for improving the QW interface quality and hence the photon emission efficiency, particularly with InN layers of no silicon doping. Then, the broadening of InGaN well layer in other sample by inserting silicon-doped InGaN interfacial layers leads to quantum dot-like structures and the strongest carrier localization. Therefore, we observe quite high photoluminescence (PL) emission efficiencies and strong photoluminescence excitation (PLE) intensity. Compared with the aforementioned samples, the normally used QW sample shows the lowest PL emission efficiencies, the lowest PL emission photon energies and the weakest PLE intensity. In other words, the addition of the InN or InGaN interfacial layers indeed can improve the optical property. Besides, we conduct nanostructure study on five ZnO nanostructure samples including the structures of films, walls and tubes. In the two thin film samples, X-ray diffraction (XRD) measurements reveal the different epitaxial relationships between the ZnO film and the sapphire substrate with different growth temperatures. From the transmission electron microscopy (TEM) images and the diffraction patterns of ZnO walls, we can confirm that a branch of the wall or a tube structure is a single crystal with the same orientation.

並列關鍵字

TEM ； GaN ； ZnO ； quantum well

參考文獻

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