Studies of V-defects on GaN Films by Micro Raman Spectroscopy
碩士 === 國立交通大學 === 電子物理系所 === 93 === The optical properties of V-defects on GaN films were characterized by using atomic force microscopy and micro-Raman spectroscopy. Raman LO related modes of 3.3�慆 V-defects show noticeable blue shifts from different doping concentration samples. For V-defects of d...
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| Format: | Others |
| Language: | en_US |
| Published: |
2005
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| Online Access: | http://ndltd.ncl.edu.tw/handle/64490779060912276336 |
| Summary: | 碩士 === 國立交通大學 === 電子物理系所 === 93 === The optical properties of V-defects on GaN films were characterized by using atomic force microscopy and micro-Raman spectroscopy. Raman LO related modes of 3.3�慆 V-defects show noticeable blue shifts from different doping concentration samples. For V-defects of different size, the appearance of forbidden Raman modes A1(TO) and E1(TO) inside V-defects is due to the right angle scattering from morphology variation. Distinct blue shift of LO related modes was also observed inside V-defects compare to the plain region, especially in large V-defects. Simulation results obtained from the phonon-plasmon interaction model suggest a higher carrier density inside V-defects than that on the plain region. Thus, we deduced a higher dislocation density (~1010cm-2) inside V-defects than that (108~109cm-2) on the plain by considering effective electron density.
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