Direct measurements of conductivity and mobility in millimeter-sized single-crystalline graphene via van der Pauw geometry
We report the direct measurements of conductivity and mobility in millimeter-sized single-crystalline graphene on SiO2/Si via van der Pauw geometry by using a home-designed four-probe scanning tunneling microscope（4P-STM）. The gate-tunable conductivity and mobility are extracted from standard van de...
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| Published in | Chinese physics B Vol. 26; no. 6; pp. 307 - 314 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
01.06.2017
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| Online Access | Get full text |
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| Summary: | We report the direct measurements of conductivity and mobility in millimeter-sized single-crystalline graphene on SiO2/Si via van der Pauw geometry by using a home-designed four-probe scanning tunneling microscope（4P-STM）. The gate-tunable conductivity and mobility are extracted from standard van der Pauw resistance measurements where the four STM probes contact the four peripheries of hexagonal graphene flakes, respectively. The high homogeneity of transport properties of the single-crystalline graphene flake is confirmed by comparing the extracted conductivities and mobilities from three setups with different geometry factors. Our studies provide a reliable solution for directly evaluating the entire electrical properties of graphene in a non-invasive way and could be extended to characterizing other two-dimensional materials. |
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| Bibliography: | graphene conductivity, mobility, four-probe measurement, van der Pauw method We report the direct measurements of conductivity and mobility in millimeter-sized single-crystalline graphene on SiO2/Si via van der Pauw geometry by using a home-designed four-probe scanning tunneling microscope（4P-STM）. The gate-tunable conductivity and mobility are extracted from standard van der Pauw resistance measurements where the four STM probes contact the four peripheries of hexagonal graphene flakes, respectively. The high homogeneity of transport properties of the single-crystalline graphene flake is confirmed by comparing the extracted conductivities and mobilities from three setups with different geometry factors. Our studies provide a reliable solution for directly evaluating the entire electrical properties of graphene in a non-invasive way and could be extended to characterizing other two-dimensional materials. Rui-Song Ma1,2,3, Qing Huan1,2,3, Liang-Mei Wu1,2,3, Jia-Hao Yan1,2,3, Yu-Yang Zhang2, Li-Hong Ba1,2,3, Yun-Qi Liu4, Shi-Xuan Du1,2,3, and Hong-Jun Gao1,2,3（ 1 Institute of Physics ＆ School of Physical Sciences, University of Chinese Academy of Sciences （CAS）, Beijing 100190, China ; 2 CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China ; 3 Beijing Key Laboratory for Nanomaterials and Nanodevices, Beijing 100190, China ; 4Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China） 11-5639/O4 |
| ISSN: | 1674-1056 2058-3834 |
| DOI: | 10.1088/1674-1056/26/6/066801 |