Vol.9 No.3 2017
Research paper : High quality and large-area graphene synthesis with a high growth rate using plasma-enhanced CVD (M. Hasegawa et al.)−138−Synthesiology - English edition Vol.9 No.3 (2017) Carbon Nanotubes (TASC) from 2011 to present. In this paper, was in charge of the plasma analysis and double-layered graphene analysis.Masatou IshiharaGraduated from the Department of Industrial Chemistry (currently Pure and Applied Chemistry), Faculty of Science and Technology, Tokyo University of Science in 1991. Researcher, Research Department, Kurami Works, Nippon Mining and Metals Co., Ltd. (currently JX Nippon Mining and Metals Corporation). Completed the doctor’s program at the Department of Materials Science and Technology, Graduate School of Industrial Science and Technology, Tokyo University of Science in 1997. Doctor (Engineering). Postdoctoral Fellow, Japan Science and Technology Agency in 1997. Joined the National Institute of Materials and Chemical Research, Agency of Industrial Science and Technology in 2000. Researcher, Research Center for Advanced Carbon Materials, AIST in 2001. Senior Researcher, Carbon-Based Thin Film Materials Group, Nanomaterials Research Institute, AIST from 2015 to present. In this paper, was in charge of the substrate pretreatment by wet method, the transfer of graphene to transparent substrate, the development of use of transparent conductive lms, and others.Takatoshi YamatakaGraduated from the Department of Electronics, School of Engineering, Tokai University in 1996. Completed the master’s program at the Department of Electronics, Graduate School of Engineering, Tokai University in 1998. Assistant, College of Science and Engineering, Aoyama Gakuin University in 1998. Assistant, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University in 2003. Joined AIST in 2004. Currently, Senior Researcher, Carbon-Based Thin Film Materials Group, Nanomaterials Research Institute. In this paper, was in charge of the impurity analysis for plasma CVD graphene and the evaluation of electrical characteristics.Yuki OkigawaGraduated from the Department of Electrical Electronic Engineering and Information Engineering, School of Engineering, Nagoya University in 2007. Completed the doctor’s program at the Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Nagoya University in 2012. Doctor (Engineering). Joined the CNT Application Research Center, AIST in 2012. Currently, Researcher, Carbon-Based Thin Film Materials Group, Nanomaterials Research Institute. In this paper, was in charge of the fabrication of device using graphene and the evaluations of electroconductivity characteristic and crystallization property of the device.Discussions with Reviewers1 OverallComment (Shuji Abe, Musashino University)This paper is very convincing as it experimentally investigates details of plasma CVD synthesis technology for graphene developed by the authors employing various original ideas, and then it empirically describes high quality graphene synthesis that has become possible through such efforts.Comment (Hiroaki Hatori, AIST)The technology that enables high-quality, high-speed, and large-area synthesis of graphene is the key in the realization of long-awaited transparent electrodes, and I think it is very interesting to see a discussion of such a technological development process in a synthesiological light. This paper is signicant in that it shows the course of R&D for the establishment of high-quality high-throughput synthesis technology for graphene transparent conductive lms using plasma CVD.2 Prospects for industrial productionQuestion and Comment (Shuji Abe)The “ultralow carbon concentration plasma CVD” does not use carbon-containing gas at all, and the materials for graphene are the carbon supplied from the impurities in copper foil and environment inside the reaction chamber, but these are factors that cannot be controlled by engineering. Certainly, we see that the crystal size is improved and the plasma treatment time is shortened in the laboratory, but do you have prospect toward industrial production?Answer (Masataka Hasegawa)Since it has become clear that the improvement of crystal size is due to the reduction of nucleus formation site in ultralow carbon concentration, monitoring the impurities in the production process is important, and forming good quality graphene films by reducing the number of nucleus formation sites is extremely important in future industrial processes. Therefore, the supply of excessive carbon reduces the quality of graphene, and impurity monitoring from the reaction chambers and others will be necessary in the industrial production. Currently, we are conducting an A4-size bench scale experiment, and continuous supply of carbon sources at optimal concentration will become necessary for large-scale continuous lm forming.3 Technological selection for achieving the goalQuestion and Comment (Hiroaki Hatori)In this paper, the background of development, the scenario, and the results based on this scenario are summarized for each elemental technology including the solution for impurity incorporation, the improvement of quality by reduction of graphene nucleus formation density, and the development of selective synthesis of double-layered graphene. Ultimately, you succeeded in the synthesis of a large-area transparent graphene conductive film. On the other hand, from the perspective of technological selection toward the final goal of realizing the transparent graphene electrode, I think the readers will better understand the overall scenario by which the authors achieved success in developing the large-area transparent graphene conductive lm if you discuss the differences of your technology against the thermal CVD method that you mention partially in this paper, and make contrasts with other competing technologies.Answer (Masataka Hasegawa)We created and inserted a table comparing the plasma CVD and the conventional thermal CVD in Chapter 7, to allow easy understanding of the superiority of the high-throughput plasma CVD method.