Isoelectronic In-doped GaN Studied by Photoluminescence and Raman Spectroscopy

• Main Authors: Chen, Chung-Cheng, 陳仲誠
• Other Authors: Lee, Ming-Chih
• Format: Others
• Language: en_US
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/10564454221584200998

碩士 === 國立交通大學 === 電子物理系 === 86 === 　　In order to investigate the effect of isoelectronic doping on the properties of GaN, In-doped GaN films grown at various temperatures, with different TrimethylIndium (TMIn) flow rates and buffer layer thicknesses were prepared and studied by Photoluminescence (PL), Raman scattering and Hall measurements. The experimental results show that under certain conditions. In-doping is effective in reducing the undesired background concentration, deep-level related emissions and line width of near band edge (NBE) emission. The analyses of our results suggest an interesting correlation between the FWHM of NBE emission and background concentration. A model based on the random distribution of defects seems to be useful in interpreting the correlation. The dependence of the intensity ratio of NBE to deep-level transition indicates that the defects accounting for the yellow luminescence should be of compensating center. From Raman spectra, the position of E2 mode and the appearance of A1(TO) and E1(TO) modes all change with the Inincorporation indicating the strain variation in the GaN thin film. The imperfect hexagonal structure appears to be improvable to some extent by In-doping. Besides, temperature dependent PL spectra and nonuniform surface occurred under high TMIn flow rate will also be discussed.