Transmission Electron Microscopy Studies of InGaN/GaN Multiple Quantum Well Nano-structures of Different Well Widths and Different Thermal Annealing Conditions
Date Issued
2004
Date
2004
Author(s)
Chen, Chun-Yang
DOI
en-US
Abstract
In this thesis, the study results of InGaN/GaN multiple quantum well structures are reported. First, we present systematical results of material analysis of five InGaN/GaN quantum well samples of the same indium content but different quantum well widths. High-resolution transmission electron microscopy (HRTEM) and strain-state analysis (SSA) images are obtained to show that different shapes of quantum-dot like clusters are formed when well width changes. Also, different degrees of the interface fluctuation are observed. The results of optical characterizations are quite consistent with material analyses. Then, we compare the post-growth thermal annealing effects on InGaN/GaN multiple quantum well structures of different annealing cooling rates. By changing the cooling rate, we investigate the changes of nano-structure. Samples of thermal annealing with the slow cooling rate have quite clear indium-rich clusters. The interfaces between the wells and barriers are quite clear and the well shapes are quite good. On the other hand, samples of thermal annealing with the fast cooling rate also have indium-rich clusters. However, their interfaces between the wells and barriers become unclear and are bended in shape. The cooling rate of the thermal annealing process can influence the sample structures and optical properties.
Subjects
氮化銦鎵
奈米結構
熱退火
Nano-structures
InGaN
Thermal Annealing
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91943111-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):ee7b0217838fd5bc7c2c0aa5893bd5bf