Synthesis of GaN Nanowires on Different Substrates by TMGa-TBHy MOCVD System

• Main Authors: Shi-En Tseng, 曾士恩
• Other Authors: Lu-Sheng Hong
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/58959999637345951290

碩士 === 國立臺灣科技大學 === 化學工程系 === 97 === Gallium nitride (GaN) nanowires have been synthesized successfully by metalorganic chemical vapor deposition (MOCVD) technique using trimethygallium (TMGa) and i-butylhydrazine (TBHy) as reactants in the first time. Emphasis of this study is placed on evaluating the possibility of using TBHy, a new nitrogen precursor with lower decomposition temperature than ammonia. By using the new nitrogen precursor can decrease process temperature in traditional MOCVD system and the carbon concentration in GaN nanowires. The best morphology and the crystal quality can be obtained in the following experimental conditions : 700℃ and V/III=31.4. The diameter and length of GaN nanowires are about 27nm and 3 μm. Then, we use six different substrates : Si(100), Si(111), Sapphire, MgO, LiAlO2 and GaN to reduce effects of the difference between lattice mismatch and thermal expansion. In the experimental results, GaN nanowires have the specific direction and the better optical quality on GaN substrate. The photoluminescence (PL) intensity which grown GaN nanowires on GaN substrate is stronger 26.6% than GaN substrate and the FWHM (full width at half maximum) of band edge emission is 86 meV. Hence, this propose makes possible further investigation of increasing the brightness of LED in TMGa-TBHy MOCVD system.