本文選題：碳納米管　切入點：等離子體氣相沉積法　出處：《電子科技大學》2015年碩士論文　論文類型：學位論文

【摘要】：碳納米管(CNT)作為制備場發(fā)射冷陰極的理想材料,具有化學性質穩(wěn)定、場發(fā)射電流密度大等優(yōu)點,碳納米管冷陰極有一個重要的用途就是可以用于高功率微波管的電子源。本文分別利用等離子體氣相沉積法、絲網印刷法以及電泳沉積法這三種方法制備得到碳納米管冷陰極樣品,并利用場發(fā)射測試儀器測試每種碳納米管冷陰極樣品的場發(fā)射性能,并對場發(fā)射測試結果進行分析研究。本文利用等離子體氣相沉積法(PECVD法)制備得到碳納米管冷陰極樣品。首先我們采用電泳沉積以及電子束蒸鍍兩種方法在襯底上鍍覆鐵催化劑顆粒層,然后利用掃描電子顯微鏡以及拉曼光譜對PECVD方法制備得到的碳納米管冷陰極樣品的表面形貌以及碳納米管的缺陷程度進行表征。通過對比SEM照片發(fā)現采用電子束蒸鍍法鍍鐵生長出的CNT的均勻性要遠遠優(yōu)于電泳沉積法鍍鐵生長出的CNT。通過對比場發(fā)射測試結果發(fā)現碳納米管的生長時間對其場發(fā)射性能也有著很大的影響。最終我們利用PECVD方法在碳納米管的生長時間控制在20min的條件下制備得到碳納米管冷陰極樣品的最大場發(fā)射電流密度達到141mA/cm2,開啟場強為1.2V/μm,閾值場強為3.8V/μm,場致發(fā)射區(qū)域的直徑為3mm。本文還利用了絲網印刷法和電泳沉積法在Si片上面制備得到具有大面積發(fā)射區(qū)域的碳納米管冷陰極樣品,由于這兩種方法屬于移植法,相比PECVD這種直接生長法制備得到的碳納米管冷陰極樣品而言,其場發(fā)射電流密度較小,但具有成本較低、工藝簡單等優(yōu)點而且場致發(fā)射面積能夠達到10mm×10mm。在利用絲網印刷法制備碳納米管冷陰極樣品時,我們研究了不同球磨時間、不同的有機漿料配比對制備得到的碳納米管冷陰極樣品的場發(fā)射性能的影響并分析其原因,最終我們利用絲網印刷法在球磨時間為2h、有機漿料配比為5:1:50的條件下制備得到碳納米管冷陰極樣品的最大電流密度達到2.8mA/cm2,開啟場強為1.5V/μm。在利用電泳沉積法制備碳納米管冷陰極樣品時,我們研究了不同的電泳時間對制備得到的碳納米管冷陰極樣品的場發(fā)射性能的影響并分析其原因,最終我們利用電泳沉積法在磁控濺射Ti膜的Si片上面電泳沉積10min的條件下制備得到碳納米管冷陰極樣品的最大電流密度達到2.5 mA/cm2,開啟場強為1.3V/μm。
[Abstract]:As an ideal material for preparing field emission cold cathode, CNT has the advantages of stable chemical properties and high field emission current density. One important application of carbon nanotube cold cathode is that it can be used as an electron source for high power microwave tube. The cold cathode samples of carbon nanotubes were prepared by screen printing and electrophoretic deposition, and the field emission properties of each kind of carbon nanotubes cold cathode samples were tested by field emission test instrument. In this paper, the cold cathode samples of carbon nanotubes were prepared by plasma vapor deposition (PECVD). Firstly, we used electrophoretic deposition and electron beam evaporation on the substrate. Coated with iron catalyst particle layer, Then the surface morphology and defect degree of carbon nanotubes (CNTs) prepared by PECVD were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. The electron beam was found by comparing SEM photos. The uniformity of CNT grown by evaporation deposition is much better than that grown by electrophoretic deposition. The results of field emission test show that the growth time of carbon nanotubes has a great influence on the field emission properties of carbon nanotubes. The maximum field emission current density of carbon nanotube cold cathode samples prepared by PECVD method is 141mA / cm ~ 2, the opening field intensity is 1.2V / 渭 m, the threshold field intensity is 3.8V / 渭 m, and the field emission region is obtained by controlling the growth time of carbon nanotubes at 20min. The maximum field emission current density of carbon nanotube cold cathode samples is 141mA / cm ~ 2, and the threshold field intensity is 3.8V / 渭 m. Using screen printing and electrophoretic deposition methods to prepare carbon nanotube cold cathode samples with large emission region on Si wafer. Because these two methods belong to the transplantation method, compared with the carbon nanotube cold cathode sample prepared by PECVD, the field emission current density is lower, but the cost is lower. The process is simple and the field emission area can reach 10mm 脳 10mm. in the preparation of carbon nanotube cold cathode samples by silk-screen printing, we have studied different milling time. The effects of different organic slurry ratios on the field emission properties of the prepared carbon nanotube cold cathode samples were analyzed. Finally, we use screen printing method to prepare carbon nanotube cold cathode sample under the condition of milling time of 2 h and organic slurry ratio of 5: 1: 50. The maximum current density of carbon nanotube cold cathode sample is 2.8 Ma / cm ~ 2 and the open field strength is 1.5 V / 渭 m. Carbon is prepared by electrophoretic deposition method. When the nanotube cold cathode sample, We studied the effect of different electrophoretic time on the field emission properties of the prepared carbon nanotube cold cathode samples and analyzed the reasons. Finally, we prepared the carbon nanotube cold cathode samples by electrophoretic deposition under the condition of 10 min electrophoretic deposition on the Si substrate of magnetron sputtering Ti film. The maximum current density and the opening field intensity of the cold cathode samples are 2.5 Ma / cm 2 and 1.3 V / 渭 m respectively.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TQ127.11;TB383.1

【參考文獻】

相關碩士學位論文 前1條

1 朱春暉;碳納米管場致發(fā)射冷陰極的研究[D];東南大學;2005年

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本文編號：1602142