CVD法制备石墨烯材料及其表征

发布时间：2018-01-10 22:15

本文关键词：CVD法制备石墨烯材料及其表征　出处：《长安大学》2016年硕士论文　论文类型：学位论文

【摘要】：在微电子和集成电路技术高速发展的今天,石墨烯由于其独特的六角结构赋予了其独特的半导体特性,成为能够取代硅材料的最理想的半导体材料,此外其还有很好的机械性能、很高的热导率和良好的透光性等很多优异性能,再加上其储量丰富,自其出现以来走进了越来越多研究者的视线。本文首先用化学沉积的方法以铜片为基片,生长了质量较好的石墨烯材料,对其进行转移并用多种手段对其进行表征测试和性能研究,本文的研究内容和结果如下:(一)用化学沉积法在铜箔上生长了石墨烯结构,表征结果表明制备的石墨烯为单层,且具有石墨烯片的典型特征。(二)研究生长参数对实验结果的影响。采取控制变量的实验方法,生长过程中依次改变甲烷和氢气分压比(7:1,8:1,9:1,10:1)和生长时间(10 min,20 min,30min,40 min)。表征结果表明,通过改变生长过程中甲烷和氢气的分压比可以控制石墨烯的厚度和层数,通过改变时间可以控制石墨烯在基片上的覆盖率,7:1分压比下生长30 min,最容易得到质量较好、尺寸较大的石墨烯。(三)为了研究铜片U型折叠放置方式对石墨烯厚度均匀性的影响,选择水平放置的铜片、折叠成U型上下层间距为5 mm、折叠成U型上下层间距为10 mm的铜片为生长基片,设计实验并从两个角度解释了生长过程中的气体动力学行为,最后对实验结果进行了预期:U型折叠放置间距较小的铜片上生长的石墨烯具有最好的厚度均一性。(四)对石墨烯的转移方法进行研究,转移后的石墨烯片状结构更为清晰;对转移到二氧化硅上的石墨烯进行原子力显微镜表征,表征结果表明,石墨烯表面较为平整,厚度较为均匀;研究了转移后退火过程对材料的影响,表征结果表明退火对于减小表面粗糙度、去除PMMA等杂质有明显作用。(五)对生长的石墨烯进行光电性能测试分析。用分光光度计和IV测试仪对石墨烯的透光率和电学性能进行测试,表征结果表明几乎不同波段的透光率都在80%以上,具有一定的导电性;制备了Graphene-AZO异质结,表征结果表明其IV曲线没有呈现整流特征,说明其没有形成势垒,还需要进一步对石墨烯掺杂进行研究。
[Abstract]:With the rapid development of microelectronics and integrated circuit technology, graphene has become the ideal semiconductor material to replace silicon because of its unique hexagonal structure. In addition, it also has good mechanical properties, high thermal conductivity and good transmittance and many other excellent properties, plus its rich reserves. Since its appearance, more and more researchers have come into view. Firstly, the graphene material of good quality was grown by chemical deposition method, using copper as substrate. The structure of graphene was grown on copper foil by chemical deposition method. The results of this study are as follows: (1) graphene structure was grown on copper foil by chemical deposition method. The characterization results show that the graphene prepared is monolayer and has the typical characteristics of graphene sheet. (2) the influence of the length parameters of graduate students on the experimental results. During the growth process, the partial pressure ratio of methane and hydrogen was changed by 7: 1: 8: 1: 9: 1: 10: 1) and the growth time was 10 min / 20 min / min ~ 30 min. The characterization results show that the thickness and the number of layers of graphene can be controlled by changing the partial pressure ratio of methane and hydrogen in the growth process, and the coverage of graphene on the substrate can be controlled by changing the time. In order to study the effect of U-fold placement on the thickness uniformity of graphene, graphene with larger size can be obtained most easily when it is grown for 30 mins at the partial pressure ratio of 7: 1, in order to study the effect of U-fold placement on the uniformity of graphene thickness. The horizontal copper sheet was selected to fold into a U-shaped upper and lower layer spacing of 5 mm, and a U-shaped upper and lower layer spacing of 10 mm copper as the growth substrate. The experiment was designed and the gas dynamic behavior during the growth process was explained from two angles. Finally, the experimental results are expected to have the best thickness uniformity of graphene grown on copper sheets with small folding spacing. (4) the transfer method of graphene is studied. The flake structure of the transferred graphene is clearer. The graphene transferred to silica was characterized by AFM. The results showed that the surface of graphene was flat and the thickness was uniform. The effect of post-transfer annealing process on the surface roughness was studied. The characterization results show that annealing can reduce the surface roughness. Removal of impurities such as PMMA has obvious effect. (5) the optoelectronic properties of graphene have been tested and analyzed. The transmittance and electrical properties of graphene have been tested by spectrophotometer and IV tester. The characterization results show that the transmittance of almost different bands is above 80%, which has a certain conductivity. Graphene-AZO heterojunction was prepared. The characterization results show that the IV curve does not exhibit rectifying characteristics, which indicates that there is no barrier, and further study on graphene doping is needed.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ127.11

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