Large-area synthesis and transfer of multilayer hexagonal boron nitride for enhanced graphene device arrays

• DOI: 10.1038/s41928-022-00911-x
• Publication Date: 2023-02-06T17:03:30Z
• Authors: Satoru Fukamachi; Pablo Solís-Ferná...; Kenji Kawahara; Daichi Tanaka; Toru Otake; Yung-Chang Lin; Kazu Suenaga; Hiroki Ago
• Keywords: 02 engineering and technology; 0210 nano-technology

AbstractMultilayer hexagonal boron nitride (hBN) can be used to preserve the intrinsic physical properties of other two-dimensional materials in device structures. However, integrating the material into large-scale two-dimensional heterostructures remains challenging due to the difficulties in synthesizing high-quality large-area multilayer hBN and combining it with other two-dimensional material layers of the same scale. Here we show that centimetre-scale multilayer hBN can be synthesized on iron–nickel alloy foil by chemical vapour deposition, and then used as a substrate and as a surface-protecting layer in graphene field-effect transistors. We also develop an integrated electrochemical transfer and thermal treatment method that allows us to create high-performance graphene/hBN heterostacks. Arrays of graphene field-effect transistors fabricated by conventional and scalable methods show an enhancement in room-temperature carrier mobility when hBN is used as an insulating substrate, and a further increase—up to a value of 10,000 cm2 V−1 s−1—when graphene is encapsulated with another hBN sheet.