Graphene with atomically smooth and configuration-specific edges plays the key role in the performance of graphene-based electronic devices.Remote hydrogen plasma etching of graphene has been proven to be an effective...Graphene with atomically smooth and configuration-specific edges plays the key role in the performance of graphene-based electronic devices.Remote hydrogen plasma etching of graphene has been proven to be an effective way to create smooth edges with a specific zigzag configuration.However,the etching process is still poorly understood.In this study,with the aid of a custom-made plasma-enhanced hydrogen etching(PEHE)system,a detailed graphene etching process by remote hydrogen plasma is presented.Specifically,we find that hydrogen plasma etching of graphene shows strong thickness and temperature dependence.The etching process of single-layer graphene is isotropic.This is opposite to the an isotropic etchi ng effect observed for bilayer and thicker graphe ne with an obvious depe ndence on temperature.On the basis of these observations,a geometrical model was built to illustrate the configuration evolution of graphene edges during etching,which reveals the origi n of the an isotropic etchi ng effect.By further utilizi ng this model,armchair graphe ne edges were also prepared in a con trolled manner for the first time.These investigations offer a better understanding of the etching process for graphene,which should facilitate the fabricati on of graphe ne?based electr onic devices with con trolled edges and the explorati on of more in teresti ng properties of graphe ne.展开更多
基金Acknowledgements This work was financially supported by the National Basic Research Program of China （Nos. 2013CB932603, 2012CB933404, 2011CB921903, and 2013CB934600）, the National Natural Science Foundation of China （Nos. 51432002, 51290272, 51121091, 51~201, and 11222434）, the Ministry of Education （No. 20120001130010） and the Beijing Municipal Sdence and Technology Planning Project （No. Z151100003315013）.
基金the National Key R&D Program of China(No.2017YFA0204901)the National Natural Science Foundation of China(Nos.21373014 and 21727806).
文摘Graphene with atomically smooth and configuration-specific edges plays the key role in the performance of graphene-based electronic devices.Remote hydrogen plasma etching of graphene has been proven to be an effective way to create smooth edges with a specific zigzag configuration.However,the etching process is still poorly understood.In this study,with the aid of a custom-made plasma-enhanced hydrogen etching(PEHE)system,a detailed graphene etching process by remote hydrogen plasma is presented.Specifically,we find that hydrogen plasma etching of graphene shows strong thickness and temperature dependence.The etching process of single-layer graphene is isotropic.This is opposite to the an isotropic etchi ng effect observed for bilayer and thicker graphe ne with an obvious depe ndence on temperature.On the basis of these observations,a geometrical model was built to illustrate the configuration evolution of graphene edges during etching,which reveals the origi n of the an isotropic etchi ng effect.By further utilizi ng this model,armchair graphe ne edges were also prepared in a con trolled manner for the first time.These investigations offer a better understanding of the etching process for graphene,which should facilitate the fabricati on of graphe ne?based electr onic devices with con trolled edges and the explorati on of more in teresti ng properties of graphe ne.
