本次論文研究主要是以使用Ti[OCH(CH3)2]4當前驅物，於垂直冷壁式有機金屬化學氣相沉積(MOCVD)系統中成長垂直成長二氧化鈦(Titanium dioxide，TiO2)奈米晶體。首先藉由在不同基板上沉積金紅石(Rutile)與銳鈦礦(Anantase)結構之二氧化鈦奈米晶體，且藉由改變前驅物溫度成功的成長小於100nm尺寸的二氧化鈦奈米晶體，接著有系統的研究退火對二氧化鈦結晶相的效應，同時探討由銳鈦礦晶相轉換成金紅石晶相與金紅石晶相經退火處理可得品質更好之退火條件。隨後利用拉曼散射光譜儀(Raman Scattering)分析晶體結晶相與晶體結構，場發射式電子顯微鏡(FESEM)觀察其表面形貌與尺寸大小，X光繞射儀(XRD)分析其晶體結晶方向，表面光電壓光譜(SPS)、光吸收光譜(absorption) 與光激發螢光光譜(PL)研究垂直成長二氧化鈦奈米結構晶體之光學特性與相關訊息。
　　由拉曼散射光譜儀分析結果，確認成長樣品二氧化鈦之晶相為金紅石結構、銳鈦礦結構，或者兩相共存，並探討所成長之二氧化鈦奈米結構之尺寸與殘留應力效應。場發射式電子顯微鏡觀察出排列整齊且緻密的金紅石與銳鈦礦結構之二氧化鈦奈米柱垂直成長在藍寶石(sapphire，SA)(100)與石英玻璃(fused silica)基板上。X光繞射儀的結果指出在藍寶石(sapphire，SA)(100)基板上的金紅石結構二氧化鈦成長方向為[001]，石英玻璃(fused silica)基板上的銳鈦礦結構二氧化鈦成長方向為[110]。利用接近能隙之表面光電壓光譜(SPS)與光吸收光譜(absorption)來決定金紅石與銳鈦礦結構二氧化鈦奈米晶體之間接能隙，分別為3.0 eV與3.2 eV(誤差為±0.02 eV)。光激發螢光光譜(PL)實驗觀察金紅石與銳鈦礦結構二氧化鈦奈米晶體，分析其光激發螢光落在2.03 eV至2.98 eV，其來自於二氧化鈦的氧缺陷所致，此外靠近紅外光區域之光激發螢光光譜(1.5 eV)是來自於金紅石結構二氧化鈦之Ti3+間隙(Ti3+ interstitial)。

We have studied the growth conditions for the deposition of rutile (R) and anatase (A) phases titanium dioxide (TiO2) nanocrystals (NCs) on various substrates via the technique of cold-wall metal organic vapor deposition (MOCVD). The source reagents used for TiO2 is Ti[OCH(CH3)2]4. Respectively, the crystalline quality of R-TiO2 NCs can be further improved upon higher annealing temperature and thermal-induced phase transformation in A-TiO2 NCs was also studied. Vertically-aligned R-TiO2 NCs were grown on sapphire SA(100) substrate. Well-aligned A-TiO2 NCs were grown on fused silica substrate. The effects of thermal annealing of TiO2 NCs in oxygen atmosphere between 900°C and 1000°C were investigated. A detailed characterization of the structural, surface morphology, orientations, optical properties of TiO2 NCs via field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman scattering (RS), photoluminescence (PL), surface photovoltage spectroscopy (SPS) and absorption.
Raman spectrum confirmed the deposition of pure rutile phase TiO2 and pure anatase phase TiO2. The Raman spectra showed the nanosize induced redshift and peak broadening of TiO2 signatures with respect to that of the bulk counterpart which can be attributed to both the size and residual stress effects. FESEM micrographs revealed the growth of vertically aligned TiO2 NCs on SA(100) and fused silica. The XRD results revealed R- TiO2 NCs with (002) orientation on SA(100) substrate, and A- TiO2 NCs on fused silica with a preferential orientation of (220). The indirect band gap of R- TiO2 and A- TiO2 were determined to be 3.0 ± 0.02 eV and 3.2 ± 0.02 eV, respectively, by analyzing near band edge surface photovoltage and absorption spectrum. The luminescence features from 2.03 eV to 2.98 eV is associated with the oxygen vacancies. The peak at 1.5 eV is ascribed to Ti3+ interstitial.

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