Graphene has been regarded as a promising material with wide applications in microelectronic devices, biosensors, fuel cells and energy storage devices owing to its unique properties, such as high carrier mobility, high thermal conductivity and high mechanical strength. How to transfer graphene onto relevant substrates while minimising resin residues and cracks deserves is a crucial point for fabricating electronic devices using graphene. The conventional graphene transfer technology based on copper etching method has been plagued by the defect of surface pollution resulting from the unresolved and remained PMMA. We herein proposed an improved copper etching method, i. e. PMMA/PVA dual support membranes method, by indroducing a layer of polyvinyl alcohol (PVA, 98％ alcoholysis) with high water solubility to serve as the barrier layer between PMMA (providing high strength) and graphene. According to the results of optical microscopy (OM) , Raman spectroscopy and electrical properties measurement, the transferred graphene with less residual, clean surface, high crystallinity and satisfactory back gate field effect transistor (BGFET) carrier mobility can be obtained through this improved copper etching method. Moreover, this method also has the advantages of both simple operation and potential universality for the transfer of other two-dimensional materials.%石墨烯具有高载流子迁移率、高热导率、高力学强度等独特性能, 可应用于微电子器件、生物传感器、燃料电池、储能器件等, 在许多领域拥有广阔的发展前景.如何转移得到少残胶、无破损的石墨烯是其在电子器件中应用必须解决的问题.常规的基于铜刻蚀法的石墨烯转移技术存在因聚甲基丙烯酸甲酯 (PMMA) 溶解不彻底、残留在石墨烯表面而造成污染的不足.鉴于此, 本工作提出了PMMA/PVA双支撑膜辅助铜刻蚀法, 即在铜刻蚀法中引入高水溶性的聚乙烯醇 (PVA, 醇解度98％) 作为高强度PMMA和石墨烯之间的阻隔层, 构成双支撑膜.光学显微镜 (OM) 、拉曼 (Raman) 光谱及电学性能测试的结果表明, 该方法转移得到的石墨烯残胶少、表面洁净, 具有高的结晶特性, 并且其背栅场效应晶体管 (BGFET) 表现出良好的载流子迁移率.此外, 该方法操作简便, 同时还是一种潜在的用于多种二维材料转移的普适技术.
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