Meškinis Š, Vasiliauskas A, Guobienė A, Talaikis M, Niaura G, Gudaitis R
Institute of Materials Science, Kaunas University of Technology K. Baršausko St. 59 LT51423 Kaunas Lithuania
Department of Organic Chemistry, Center for Physical Sciences and Technology Saulėtekio av. 3 LT-10257 Vilnius Lithuania.
RSC Adv. 2022 Jun 28;12(29):18759-18772. doi: 10.1039/d2ra02370a. eCollection 2022 Jun 22.
In the present research, graphene was synthesized directly on a Si(100) substrate combining direct microwave plasma-enhanced chemical vapor deposition and protective enclosure. The graphene flake orientation was controlled using suitable synthesis conditions. We revealed that high processing temperatures and plasma powers promote vertical graphene growth. The main related physical mechanisms were raised temperature gradients, thermal stress, ion bombardment, and elevated electric field effects. Lowering the synthesis temperature and plasma power resulted in planar graphene growth. An elevated synthesis temperature and long deposition time decreased the graphene layer number as the carbon desorption rate increased with temperature. Dominating defect types and their relationships to the graphene growth conditions were revealed. Planar graphene n-type self-doping was found due to substrate-based charge transfer. In the case of vertical graphene, the increased contact area between graphene and air resulted in the adsorption of more molecules, resulting in no doping or p-type doping.
在本研究中，通过结合直接微波等离子体增强化学气相沉积和保护罩，在Si(100)衬底上直接合成了石墨烯。利用合适的合成条件控制石墨烯薄片的取向。我们发现，较高的加工温度和等离子体功率促进了垂直石墨烯的生长。主要相关物理机制为温度梯度升高、热应力、离子轰击和电场增强效应。降低合成温度和等离子体功率导致平面石墨烯生长。随着合成温度升高和沉积时间延长，由于碳脱附率随温度升高而增加，石墨烯层数减少。揭示了主要的缺陷类型及其与石墨烯生长条件的关系。发现平面石墨烯由于基于衬底的电荷转移而存在n型自掺杂。在垂直石墨烯的情况下，石墨烯与空气之间增加的接触面积导致更多分子的吸附，从而不产生掺杂或产生p型掺杂。
