中国物理B ›› 2023, Vol. 32 ›› Issue (6): 66103-066103.doi: 10.1088/1674-1056/acbc6a

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Er intercalation and its impact on transport properties of epitaxial graphene

Mingmin Yang(杨明敏), Yong Duan(端勇), Wenxia Kong(孔雯霞), Jinzhe Zhang(章晋哲), Jianxin Wang(王剑心), and Qun Cai(蔡群)   

  1. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
  • 收稿日期:2022-10-31 修回日期:2023-01-24 接受日期:2023-02-16 出版日期:2023-05-17 发布日期:2023-05-24
  • 通讯作者: Qun Cai E-mail:qcai@fudan.edu.cn
  • 基金资助:
    Project supported by the Natural Science Foundation of Shanghai Science and Technology Committee (Grant No. 18ZR1403300).

Er intercalation and its impact on transport properties of epitaxial graphene

Mingmin Yang(杨明敏), Yong Duan(端勇), Wenxia Kong(孔雯霞), Jinzhe Zhang(章晋哲), Jianxin Wang(王剑心), and Qun Cai(蔡群)   

  1. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
  • Received:2022-10-31 Revised:2023-01-24 Accepted:2023-02-16 Online:2023-05-17 Published:2023-05-24
  • Contact: Qun Cai E-mail:qcai@fudan.edu.cn
  • Supported by:
    Project supported by the Natural Science Foundation of Shanghai Science and Technology Committee (Grant No. 18ZR1403300).

摘要: Intercalation of atomic species is a practicable method for epitaxial graphene to adjust the electronic band structure and to tune the coupling between graphene and SiC substrate. In this work, atomically flat epitaxial graphene is prepared on 4H-SiC(0001) using the flash heating method in an ultrahigh vacuum system. Scanning tunneling microscopy, Raman spectroscopy and electrical transport measurements are utilized to investigate surface morphological structures and transport properties of pristine and Er-intercalated epitaxial graphene. It is found that Er atoms are intercalated underneath the graphene layer after annealing at 900 ℃, and the intercalation sites of Er atoms are located mainly at the buffer-layer/monolayer-graphene interface in monolayer domains. We also report the different behaviors of Er intercalation in monolayer and bilayer regions, and the experimental results show that the diffusion barrier for Er intercalated atoms in the buffer-layer /monolayer interface is at least 0.2 eV higher than that in the first/second graphene-layer interface. The appearance of Er atoms is found to have distinct impacts on the electronic transports of epitaxial graphene on SiC(0001).

关键词: epitaxial graphene, intercalation, scanning tunneling microscopy (STM), electrical transport

Abstract: Intercalation of atomic species is a practicable method for epitaxial graphene to adjust the electronic band structure and to tune the coupling between graphene and SiC substrate. In this work, atomically flat epitaxial graphene is prepared on 4H-SiC(0001) using the flash heating method in an ultrahigh vacuum system. Scanning tunneling microscopy, Raman spectroscopy and electrical transport measurements are utilized to investigate surface morphological structures and transport properties of pristine and Er-intercalated epitaxial graphene. It is found that Er atoms are intercalated underneath the graphene layer after annealing at 900 ℃, and the intercalation sites of Er atoms are located mainly at the buffer-layer/monolayer-graphene interface in monolayer domains. We also report the different behaviors of Er intercalation in monolayer and bilayer regions, and the experimental results show that the diffusion barrier for Er intercalated atoms in the buffer-layer /monolayer interface is at least 0.2 eV higher than that in the first/second graphene-layer interface. The appearance of Er atoms is found to have distinct impacts on the electronic transports of epitaxial graphene on SiC(0001).

Key words: epitaxial graphene, intercalation, scanning tunneling microscopy (STM), electrical transport

中图分类号:  (Structure of graphene)

  • 61.48.Gh
68.37.Ef (Scanning tunneling microscopy (including chemistry induced with STM)) 72.80.Vp (Electronic transport in graphene) 68.37.-d (Microscopy of surfaces, interfaces, and thin films)