本論文旨在探討熱退火溫度(thermal annealing temperature)對奈米碳管披覆金屬氧化物的影響。以矽為基板(substrate)成長多壁式奈米碳管(multiwall carbon nanotubes, MWCNT)，然而成長後的奈米碳管對外界的光照並無任何反應，因此需要在管體表面披覆金屬氧化物當光轉換層(photoconversion layer)。本研究使用有機金屬化學氣相沉積(metal organic chemical vapor deposition, MOCVD) 將TiO2披覆於奈米碳管上做為異質結構(heterojunction)的光轉換層。利用熱退火(thermal annealing)溫度變化的方式，改變披覆金屬氧化物的結晶性。使用掃描式電子顯微鏡(SEM)及穿透式電子顯微鏡（TEM）觀察熱退火溫度變化對表面晶體結構的影響。最後透過電性量測結果討論表面結晶對於光電效率(photoelectric efficiency)的影響，完成找尋最佳熱退火溫度點的目標。本論文另一研究重點，以垂直生長的奈米碳管(vertically aligned carbon nanotube, VACNT)為主體製作場發射。VACNT管束為主體的場發射，其管束間表面的單位圖案分佈會影響完成後的FE特性，因此本文將討論表面配置的單位圖案為六邊形(hexagonal)與正方形(square)，找尋這兩種單位圖案的FE特性。實驗透過光微影技術(photolithography)預設VACNT生長區域範圍，再利用熱化學氣相沉積法(TCVD)合成生長VACNT管束。實驗結果顯示使用六角形表面配置 (D/H)比的2倍有最低臨界電場與較高的增強因子，正方形表面配置（D/H）比的3倍具有最穩定的場發射（FE）的特點。觀察合成VACNT束的螢光圖像，顯示FE電流的均勻性。研究結果說明VACNT場發射的表面配置，用於發展最佳的FE性能是可行的。

In this thesis, the effect and physical mechanism of thermal annealing temperature on the photoconduction efficiency of titanium dioxide nanotube are mainly investigated. The multiwall carbon nanotubes (MWCNT) produced on silicon substrate has no response to external illumination. Therefore, a photoconversion layer coated on the tube surface is needed. This study demonstrates a heterojunction of TiO2 coated carbon nanotube photoconversion layer via metal organic chemical vapor deposition (MOCVD), transforming the crystallinity of metal-coated oxide by employing the temperature change of thermal annealing. The variation of thermal annealing temperature change to the surface structure of crystal is examined via both scanning electron microscope (SEM) and transmission electron microscope (TEM). Eventually, discussing the influence of surface crystallization to the photoelectric efficiency by measuring the electrical property, and completing the exploration of the ultimate temperature point for thermal annealing. The configuration of emitter plays an important role on the characteristics of field emission (FE). The arrangement of the field emission will determine the screening effect and the number-density of emitter. In this study, the field emitter is made of vertically aligned carbon nanotube (VACNT) bundles fabricated using thermal chemical vapor deposition (TCVD), and the pattern of arragnement is defined via photolithography. In FE characterisitics, the arrangement of emitters and the ratio of inter-bundle distance to bundle height (D/H) were investigated. The experiemental results show that a hexagon arrangement with 2 times of the D/H ratio has the lowest threshold electric field and higher enhancement factor, while an square arrangement with 3 times of the D/H has the most stable FE characteristic. The fluorescence images of the synthesized VACNT bundles also prove the uniformity of FE current. The results of this study have demonstrated the feasibility to develop optimized FE by considering the arrangement of VACNT field emitter.

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