發(fā)布時(shí)間：2018-03-21 14:24

  本文選題：場(chǎng)發(fā)射　切入點(diǎn)：碳納米管　出處：《華東師范大學(xué)》2015年博士論文　論文類型：學(xué)位論文

【摘要】：碳納米管具有優(yōu)異的電學(xué)、力學(xué)和熱學(xué)性能,在場(chǎng)發(fā)射領(lǐng)域顯示出良好的應(yīng)用前景。但是,碳納米管在發(fā)射點(diǎn)密度、發(fā)射穩(wěn)定性、均勻性,以及柔性器件制備工藝的兼容性等方面還存在許多問(wèn)題。碳納米管薄膜場(chǎng)發(fā)射性能的改善以及薄膜制備工藝的優(yōu)化是其走向產(chǎn)業(yè)化應(yīng)用的重要一步。為了推動(dòng)碳納米管薄膜場(chǎng)發(fā)射器件的實(shí)用化發(fā)展,本論文以系統(tǒng)地改善碳納米管薄膜的場(chǎng)發(fā)射性能、擴(kuò)展碳納米管薄膜場(chǎng)發(fā)射器件的應(yīng)用范圍、優(yōu)化和發(fā)展柔性碳納米管場(chǎng)發(fā)射器件的制備工藝為目標(biāo),分別對(duì)碳納米管及其復(fù)合薄膜的場(chǎng)發(fā)射性能、低真空下碳納米管薄膜的場(chǎng)發(fā)射性能以及柔性碳納米管器件的場(chǎng)發(fā)射性能進(jìn)行了探索性的研究。主要工作包括以下內(nèi)容：(1)通過(guò)在絲網(wǎng)印刷制備的碳納米管薄膜上旋涂二氧化鈦溶膠,大幅度提高碳納米管薄膜的場(chǎng)發(fā)射性能,包括顯著降低其開(kāi)啟電場(chǎng)和閾值電場(chǎng),明顯提高電子發(fā)射穩(wěn)定性。另外,還進(jìn)一步通過(guò)控制二氧化鈦溶膠反應(yīng)時(shí)間和涂覆厚度實(shí)現(xiàn)了對(duì)碳納米管/二氧化鈦復(fù)合電極場(chǎng)發(fā)射性能的控制,獲得了迄今為止場(chǎng)發(fā)射性能最佳的復(fù)合薄膜：超低的開(kāi)啟電場(chǎng)和閾值電場(chǎng),優(yōu)良的發(fā)射電流密度穩(wěn)定性。(2)系統(tǒng)地研究了氧化性氣體(空氣)和非氧化性氣體(氮?dú)夂蜌鍤?氛圍中,不同氣壓對(duì)絲網(wǎng)印刷制備的碳納米管薄膜的場(chǎng)發(fā)射性能的影響。無(wú)論在氧化性氣氛還是非氧化性氣氛中,碳納米管的場(chǎng)發(fā)射性能隨著氣壓的上升而下降。但是碳納米管的場(chǎng)發(fā)射性能在氧化性氣氛中衰減的更快。針對(duì)在氣體吸附、氣體離子碰撞以及焦耳熱等三種機(jī)制下解釋了不同氣氛中,氣體對(duì)碳納米管薄膜場(chǎng)發(fā)射性能的影響。另外,還利用二氧化鈦復(fù)合的碳納米管薄膜作為場(chǎng)發(fā)射陰極代替純碳納米管薄膜陰極,顯著改善了低真空下的碳納米管薄膜的場(chǎng)發(fā)射性能,拓展了碳納米管場(chǎng)發(fā)射器件的應(yīng)用。(3)通過(guò)石墨烯與碳納米管的復(fù)合,形成石墨烯/碳納米管復(fù)合場(chǎng)發(fā)射陰極,明顯提高了碳納米管薄膜的場(chǎng)發(fā)射性能。石墨烯與碳納米管的復(fù)合,降低了碳納米管薄膜與銀襯底的接觸勢(shì)壘,提升了電子傳輸效率。另外,還通過(guò)控制復(fù)合薄膜中石墨烯的含量、對(duì)比復(fù)合薄膜的制備方法系統(tǒng)地優(yōu)化了復(fù)合薄膜的場(chǎng)發(fā)射性能。(4)憑借半固化的有機(jī)硅(Polydimethylsiloxane, PDMS)柔性襯底的獨(dú)特性能,通過(guò)結(jié)合真空抽濾法和簡(jiǎn)單的膜轉(zhuǎn)移技術(shù)成功制備了全碳納米管柔性場(chǎng)發(fā)射器件,并系統(tǒng)研究了器件彎曲方向和彎曲程度對(duì)柔性器件場(chǎng)發(fā)射性能的影響及其影響機(jī)理。
[Abstract]:Carbon nanotubes (CNTs) have excellent electrical, mechanical and thermal properties. In situ emission field, CNTs show a good prospect of application. However, CNTs are characterized by emission point density, emission stability and uniformity. The improvement of carbon nanotube film field emission performance and the optimization of film preparation process are important steps for its industrial application. The practical Development of Nanotube thin Film Field Emission Devices, The purpose of this thesis is to improve systematically the field emission performance of carbon nanotubes (CNTs) thin films, to expand the application range of CNT film field emission devices, and to optimize and develop the fabrication process of flexible CNT field emission devices. Field emission properties of carbon nanotubes and their composite films, The field emission properties of carbon nanotube thin films and the field emission properties of flexible carbon nanotube devices were investigated in low vacuum. The main work includes the following contents: 1) the carbon nanotube films prepared by screen printing. Spin coated titanium dioxide sol, The field emission properties of carbon nanotube films are greatly improved, including the significant reduction of the opening electric field and threshold electric field, and the significant improvement of the stability of electron emission. Furthermore, the field emission performance of carbon nanotube / titanium dioxide composite electrode was controlled by controlling the reaction time and coating thickness of titanium dioxide sol. The composite films with the best field emission performance up to now have been obtained: ultra-low open electric field and threshold electric field, The excellent stability of emission current density is studied systematically in the atmosphere of oxidizing gas (air) and non-oxidizing gas (nitrogen and argon). Effects of different pressure on field emission properties of carbon nanotube films prepared by screen printing. The field emission properties of carbon nanotubes decrease with the increase of atmospheric pressure. However, the field emission properties of carbon nanotubes decay more rapidly in oxidizing atmospheres. The effects of gases on the field emission properties of carbon nanotube films in different atmospheres are explained under the three mechanisms of gas ion collision and joule heat. The field emission properties of carbon nanotube films under low vacuum were improved by using titanium dioxide composite carbon nanotube film as field emission cathode instead of pure carbon nanotube film cathode. The application of carbon nanotube field emission devices is expanded. The composite field emission cathodes of graphene / carbon nanotubes are formed by the combination of graphene and carbon nanotubes. The composite of graphene and carbon nanotube reduces the contact barrier between carbon nanotube film and silver substrate and improves the electron transport efficiency. By controlling the content of graphene in the composite films, the field emission properties of the composite films were systematically optimized by comparing the preparation methods of the composite films. The unique properties of the flexible substrates of polydimethylsiloxane (PDMS) were optimized by means of semi-curable organosilicon polymethylsiloxane (PDMS). The flexible field emission devices of full carbon nanotubes (CNTs) were successfully fabricated by vacuum filtration and simple membrane transfer techniques. The effects of bending direction and bending degree on the field emission properties of flexible devices and their influencing mechanisms were systematically studied.
【學(xué)位授予單位】：華東師范大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33;TQ127.11

【共引文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 程祖華;場(chǎng)發(fā)射陰極OLED器件的結(jié)構(gòu)及性能研究[D];鄭州大學(xué);2014年

2 徐曉偉;TFT-LCD閃爍測(cè)試系統(tǒng)設(shè)計(jì)[D];上海交通大學(xué);2013年

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本文編號(hào)：1644244