• 文献标题:   Increasing the doping efficiency by surface energy control for ultra-transparent graphene conductors
  • 文献类型:   Article
  • 作  者:   CHANG KW, HSIEH YP, TING CC, SU YH, HOFMANN M
  • 作者关键词:  
  • 出版物名称:   SCIENTIFIC REPORTS
  • ISSN:   2045-2322
  • 通讯作者地址:   Natl Taiwan Univ
  • 被引频次:   1
  • DOI:   10.1038/s41598-017-09465-x
  • 出版年:   2017

▎ 摘  要

Graphene's attractiveness in many applications is limited by its high resistance. Extrinsic doping has shown promise to overcome this challenge but graphene's performance remains below industry requirements. This issue is caused by a limited charge transfer efficiency (CTE) between dopant and graphene. Using AuCl3 as a model system, we measure CTE as low as 5% of the expected values due to the geometrical capacitance of small adsorbate clusters. We here demonstrate a strategy for enhancing the CTE by a two-step optimization of graphene's surface energy prior to AuCl3 doping. First, exposure to UV ozone modified the hydrophilicity of graphene and was found to decrease the cluster's geometric capacitance, which had a direct effect on the CTE. Occurrence of lattice defects at high UV exposure, however, deteriorated graphene's transport characteristics and limited the effectiveness of this pretreatment step. Thus, prior to UV exposure, a functionalized polymer layer was introduced that could further enhance graphene's surface energy while protecting it from damage. Combination of these treatment steps were found to increase the AuCl3 charge transfer efficiency to 70% and lower the sheet resistance to 106 Omega/gamma at 97% transmittance which represents the highest reported performance for doped single layer graphene and is on par with commercially available transparent conductors.