本文關(guān)鍵詞： 石墨烯 絕緣襯底 熱化學(xué)氣相沉積 快速升溫　出處：《昆明理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：石墨烯是由碳原子以sp2雜化連接組成的,自從2004年問世之后,石墨烯因?yàn)閾碛刑禺惖慕Y(jié)構(gòu)和杰出的物理化學(xué)特性,很快便引起了科學(xué)界和商業(yè)界的高度關(guān)注。本文采用熱化學(xué)氣相沉積(CVD)的方法,以甲烷(CH4)作為碳源,氫氣(H2)作為反應(yīng)氣體,氬氣(Ar)作為運(yùn)載氣體,探究了直接在SiO2/Si和石英襯底上生長石墨烯的工藝,并通過拉曼光譜、掃描電子顯微鏡、能譜散射光譜和透射電子顯微鏡等技術(shù)手段對(duì)獲得的石墨烯進(jìn)行了表征。通過設(shè)計(jì)對(duì)比性實(shí)驗(yàn),研究石墨烯生長過程中升溫方式、冷卻速率、催化層厚度以及生長時(shí)間對(duì)其質(zhì)量和層數(shù)的影響,探索制備高質(zhì)量大面積石墨烯的最佳工藝參數(shù)。測試結(jié)果表明,當(dāng)冷卻速率很快時(shí),得到的產(chǎn)物的2D峰有明顯的分峰現(xiàn)象,可能是石墨；當(dāng)冷卻速率很慢時(shí),在Ni膜的上面和下面都得不到石墨烯。當(dāng)Ni膜厚度分別為100,200,300 nm時(shí),在Ni膜的上面以及絕緣襯底和Ni膜的界面處都獲得了多層或者少數(shù)層數(shù)的石墨烯,當(dāng)Ni膜厚度為400 nm時(shí),拉曼表征顯示,只在Ni膜的上面獲得了石墨烯,在絕緣襯底和Ni膜的界面處沒有任何石墨烯的信號(hào)。不同的生長時(shí)間(5,10,20 min)對(duì)石墨烯的生長也會(huì)產(chǎn)生影響,當(dāng)生長時(shí)間只有5min時(shí),在絕緣襯底和Ni膜的界面處雖然獲得了石墨烯的信號(hào),但是經(jīng)過四探針測試儀表征發(fā)現(xiàn),得到的石墨烯膜沒有電阻,說明當(dāng)生長時(shí)間太短時(shí),石墨烯膜不連續(xù)。當(dāng)生長時(shí)間延長至20min時(shí),可以在絕緣襯底和Ni膜的界面處獲得連續(xù)的石墨烯膜。采用熱CVD的方法,通過快速升溫的方式,在氣體流量和流量比為H2/CH4 =20/5sccm、生長溫度為950℃、生長時(shí)間為20min、催化層Ni膜300nm以及快速冷卻的條件下,在SiO2/Si襯底和石英襯底上獲得了高質(zhì)量的單層石墨烯。
[Abstract]:Graphene is composed of carbon atoms connected by sp2 hybrids. Since its inception in 2004, graphene has been characterized by its unique structure and outstanding physical and chemical properties. In this paper, the method of thermochemical vapor deposition (CVD), methane (CH4) as carbon source, hydrogen (H2) as reaction gas. Ar as a carrier gas, the growth process of graphene on SiO2/Si and quartz substrates was investigated. Raman spectra and scanning electron microscopy (SEM) were used. The graphene was characterized by energy dispersive spectroscopy and transmission electron microscope. The temperature rise and cooling rate during the growth of graphene were studied by designing comparative experiments. The effects of the thickness of catalyst layer and growth time on the quality and number of layers were investigated to explore the optimum process parameters for the preparation of high quality and large area graphene. The results showed that the cooling rate was very fast. The 2D peak of the obtained product has obvious peak splitting phenomenon, which may be graphite. When the cooling rate is very slow, graphene can not be obtained at the top and bottom of the Ni film, and when the thickness of the Ni film is 100,200,300 nm, respectively. Several layers or a few layers of graphene were obtained on the top of the Ni film and at the interface between the insulating substrate and the Ni film. When the thickness of the Ni film is 400 nm, the Raman characterization shows that. Graphene was obtained only on the top of the Ni film, and there was no signal of graphene at the interface between the insulating substrate and the Ni film. When the growth time was only 5 min, the signal of graphene was obtained at the interface between the insulating substrate and the Ni film. However, it was found that the graphene film had no resistance, which indicated that the graphene film was discontinuous when the growth time was too short, and when the growth time was extended to 20 min. A continuous graphene film can be obtained at the interface between the insulating substrate and the Ni film. The thermal CVD method is used to increase the temperature rapidly. Under the conditions of gas flow and flow ratio of H _ 2 / Ch _ 4 20 / 5 sccm, growth temperature 950 鈩，

本文編號(hào)：1493768