Photoluminescence Spectrum of LT-GaAs and Raman study of AlAsSb

• Main Authors: Shwu-Ping Lin, 林淑萍
• Other Authors: Wei-Kuo Chen
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/83360719206450754571

碩士 === 國立交通大學 === 電子物理學系 === 83 === We use Photoluminescence(PL) spectrum to investigate the low temperature gallium arsenide films (LT-GaAs), grown by the metalorganic chemical vapor deposition(MOCVD)method, using TEGa and TBAs as source precursor. For samples grown below 550C, we find there are two deep levels at 1.219eV and 1.356 eV below conduction band. It is confirmed that these traps are caused from the gallium vacancy and its releated defect. For comparison the sample using arsine doesn't show any relevant peaks. Therefore, we conclude that the origion of such defects may associate with the use of TBAs presursor, particularly at low growth temperature. In the second part of the thesis, Raman spectroscopy was emplyed to characterize the long-wavelength optical-mode behavior of AlAsSb alloys for a variety of Sb mole fract- ions. The cap layer play the important role in our Raman measurement. Because the AlAsSb films are not stable ,we can't get the enough information to judge their optical mode. From the limited data obtained from experiment, it seems likely that AlAsSb alloys belong to the single-mode behavior.