Large‐Area Synthesis of Superclean Graphene via Selective Etching of Amorphous Carbon with Carbon Dioxide

Abstract

Contamination commonly observed on the graphene surface is detrimental to its excellent properties and strongly hinders its application. It is still a great challenge to produce large‐area clean graphene film in a low‐cost manner. Herein, we demonstrate a facile and scalable chemical vapor deposition approach to synthesize meter‐sized samples of superclean graphene with an average cleanness of 99 %, relying on the weak oxidizing ability of CO2 to etch away the intrinsic contamination, i.e., amorphous carbon. Remarkably, the elimination of amorphous carbon enables a significant reduction of polymer residues in the transfer of graphene films and the fabrication of graphene‐based devices and promises strongly enhanced electrical and optical properties of graphene. The facile synthesis of large‐area superclean graphene would open the pathway for both fundamental research and industrial applications of graphene, where a clean surface is highly needed.

Controllable synthesis of graphene by CVD method

“…撑的CLT(clean-lifting transfer)转移方法, 在洁净石墨烯 的道路上做了一系列探索. 近期, 研究发现石墨烯表面 在生长过程中所吸附的无定形碳也是影响石墨烯洁净 程度的重要原因, 并通过设计含铜碳源 [62] 、新型泡沫 铜基底结构 [63] 、CO 2 选择性刻蚀 [128] , 以及活性碳基棉 绒辊 In 2004, graphene was successfully prepared by micromechanical exfoliation of graphite, which attracts wide attention in the scientific research community. After that, related research of two-dimensional (2D) materials has received continuous exploration.…”

Superclean Growth of Graphene Using a Cold‐Wall Chemical Vapor Deposition Approach

“…The past years have witnessed tremendous progress in the control over the domain size, layer number, flatness, and doping level . However, the contamination on the surface of CVD graphene has been widely reported to highly degrade the intrinsic properties of graphene, making CVD graphene not comparable to its mechanically exfoliated counterpart . Meanwhile, surface contamination would hinder the applications of CVD‐derived graphene, especially when a clean surface is needed …”

“…According to observed defective structure in amorphous carbon, the carbon cluster containing a 5‐8‐5 defect was used to compare the probability for a large carbon cluster to grow larger by capturing moving CH 3 species in the gas phase at different temperatures (Figure f). AIMD simulation results showed that at low temperature (700 °C) it took CH 3 species 3.8 ps to be captured by the pentagonal ring of the cluster (Figure g), while at high temperature (1000 °C) the time for capturing CH 3 species by the pentagonal ring was shortened to only 0.2 ps, and within 0.7 ps, another CH 3 would be also captured by the octagonal ring of the cluster, respectively (Figure h).…”

Activated‐Carbon Nanofibers/Graphene Nanocomposites and Their Adsorption Performance Towards Carbon Dioxide

“…Out of these mentioned adsorbents, the carbon-based ones are the most abundant and can be attained from inexpensive carbon precursors. Activated carbon (AC) [5], carbon fibers, carbon nanotubes (CNT), graphene [6], and AC nanofibers (ACNF) [7] are examples of carbonbased adsorbents that are currently used in CO 2 adsorption.…”