Vapor–liquid–solid growth of large-area multilayer hexagonal boron nitride on dielectric substrates

• Published in: Nature communications Vol. 11; no. 1; pp. 849 - 8
• Main Authors: Shi, Zhiyuan, Wang, Xiujun, Li, Qingtian, Yang, Peng, Lu, Guangyuan, Jiang, Ren, Wang, Huishan, Zhang, Chao, Cong, Chunxiao, Liu, Zhi, Wu, Tianru, Wang, Haomin, Yu, Qingkai, Xie, Xiaoming
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.02.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/357/1018; 639/925/357/1018; Boron; Boron nitride; Dielectrics; Electronic devices; Fabrication; Heterostructures; Humanities and Social Sciences; multidisciplinary; Multilayers; Nitrogen atoms; Optoelectronic devices; Sapphire; Science; Science (multidisciplinary); Substrates; Synthesis; Thickness; Two dimensional materials; Vapors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-14596-3

Multilayer hexagonal boron nitride ( h -BN) is highly desirable as a dielectric substrate for the fabrication of two-dimensional (2D) electronic and optoelectronic devices. However, the controllable synthesis of multilayer h -BN in large areas is still limited in terms of crystallinity, thickness and stacking order. Here, we report a vapor–liquid–solid growth (VLSG) method to achieve uniform multilayer h -BN by using a molten Fe 82 B 18 alloy and N 2 as reactants. Liquid Fe 82 B 18 not only supplies boron but also continuously dissociates nitrogen atoms from the N 2 vapor to support direct h -BN growth on a sapphire substrate; therefore, the VLSG method delivers high-quality h -BN multilayers with a controllable thickness. Further investigation of the phase evolution of the Fe-B-N system reveals that isothermal segregation dominates the growth of the h -BN. The approach herein demonstrates the feasibility for large-area fabrication of van der Waals 2D materials and heterostructures. Multilayer hexagonal boron nitride (hBN) is a desirable dielectric substrate for 2D electronics but its controllable synthesis is challenging. Here, the authors report a vapor–liquid–solid growth method to achieve uniform multilayer hBN by using a molten Fe 82 B 18 alloy and N 2 as reactants.