Wang Ping, Lee Woncheol, Corbett Joseph P, Koll William H, Vu Nguyen M, Laleyan David Arto, Wen Qiannan, Wu Yuanpeng, Pandey Ayush, Gim Jiseok, Wang Ding, Qiu Diana Y, Hovden Robert, Kira Mackillo, Heron John T, Gupta Jay A, Kioupakis Emmanouil, Mi Zetian
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
Department of Physics, Ohio State University, Columbus, OH, 43210, USA.
Adv Mater. 2022 May;34(21):e2201387. doi: 10.1002/adma.202201387. Epub 2022 Apr 21.
Monolayer hexagonal boron nitride (hBN) has been widely considered a fundamental building block for 2D heterostructures and devices. However, the controlled and scalable synthesis of hBN and its 2D heterostructures has remained a daunting challenge. Here, an hBN/graphene (hBN/G) interface-mediated growth process for the controlled synthesis of high-quality monolayer hBN is proposed and further demonstrated. It is discovered that the in-plane hBN/G interface can be precisely controlled, enabling the scalable epitaxy of unidirectional monolayer hBN on graphene, which exhibits a uniform moiré superlattice consistent with single-domain hBN, aligned to the underlying graphene lattice. Furthermore, it is identified that the deep-ultraviolet emission at 6.12 eV stems from the 1s-exciton state of monolayer hBN with a giant renormalized direct bandgap on graphene. This work provides a viable path for the controlled synthesis of ultraclean, wafer-scale, atomically ordered 2D quantum materials, as well as the fabrication of 2D quantum electronic and optoelectronic devices.
单层六方氮化硼（hBN）已被广泛视为二维异质结构和器件的基本构建单元。然而，hBN及其二维异质结构的可控且可扩展合成仍然是一项艰巨的挑战。在此，我们提出并进一步展示了一种用于高质量单层hBN可控合成的hBN/石墨烯（hBN/G）界面介导生长过程。研究发现，面内hBN/G界面能够被精确控制，从而实现单向单层hBN在石墨烯上的可扩展外延生长，该单层hBN呈现出与单畴hBN一致的均匀莫尔超晶格，且与底层石墨烯晶格对齐。此外，还确定了6.12 eV处的深紫外发射源于单层hBN的1s激子态，其在石墨烯上具有巨大的重整化直接带隙。这项工作为超清洁、晶圆级、原子有序的二维量子材料的可控合成以及二维量子电子和光电器件的制造提供了一条可行的途径。
