The Study of Novel Carbon Nitride Nanotubestransparent Conductive Film for Triode Field Emission Flat Light Source

Abstract

奈米碳管具有優越的場電子發射性能，關於奈米碳管在場發射性能研究一直是奈米碳管應用研究的熱門焦點之一。藉由氮元素的摻雜是有效控制奈米碳管電學性能的方法。而摻雜奈米碳管普遍具有類似金屬的性質，使得其隧道導電率及電子傳輸性能比多壁奈米碳管較為優越，因此在場發射元件的應用上具有其應用的潛力。本研究計劃是以奈米Fe-Ce觸媒粉末以化學氣相沉積法來成長所需要的碳氮奈米管。進而將成長後所得之碳氮奈米管進行不同官能基化的表面改質，加入過氧化氫以及硝酸，與碳管進行氧化反應，利用強氧化劑使其氧化成羧基(-COOH)親水性較高官能基的之碳氮奈米管。並以XRD、FTIR、TEM、TGA及拉曼光譜進行對碳氮奈米管其微結構及組成分析。將改質後之碳管均勻分散於由Sol-gel方法製備之AZO凝膠中混合成碳氮奈米管墨水。並利用線棒塗佈技術，將此碳管墨水塗佈於玻璃基板上，製備出可應用於場發射陰極的碳氮奈米管透明導電膜。並利用含有背閘極的場發射三極元件來降低操作電壓。碳氮奈米管透明導電膜及場發射元件將使用UV/VIS、FE-SEM、AFM and XPS等儀器分析其構造與表面形態，以場發射量測探討分析碳氮奈米管透明導電膜的場發射之特性。

Carbon nanotubes (CNTs) have been recently interested and focused in the area of fieldemission applications due to their excellent electronic and structural properties. Controllingthe electronic properties of CNTs via the doping N atoms related to carbon network is apossible way or direction to enhance its electric properties for better applications in fieldemission. Comparing with the multi-walled carbon nanotubes, the carbon nitride nanotubes(CNxNTs) are predicted with high potential for applications in field emission devices due tothat the doped CNTs generally reveal well-defined metallic behaviors and possess the highertunneling conductance, better electron transmission and lower resistance.This study will use the nano Fe-Ce catalyst to synthesize CNxNTs by Chemical VaporDeposition method. Then, the strong oxidants, such as HNO3 and H2O2, have been applied tooxidize the CNxNTs to form carboxylic acid group with higher hydrophilic property on thesurface. XRD, FTIR, TEM, TGA and Raman microscopy techniques have been employed todetermine the microstructure and elemental composition of the modified CNxNTs. To usethe modified CNxNTs as conductive filler and blend with AZO gel prepared by sol-gelmethod to obtain the CNxNTs ink. By using ware-bar coating method, the CNxNTs ink isprinted on glass substrate to prepare the CNxNTs transparent conductive film for fieldemission cathode. Utilizing triode-typed CNT field emission device which has under-gateelectrode to reduce the operation voltage. The analysis of the surface morphology andstructural properties of the CNxNTs transparent conductive film and triode-typed fieldemission device can be investigated by UV/VIS, FE-SEM, AFM and XPS. The fieldemission capability characteristics of the CNxNTs transparent conductive film will be alsomeasured by field emission apparatus.