title: Large-roll growth of 25-inch hexagonal BN monolayer film for self-release buffer layer of free-standing GaN wafer.
abstract: Hexagonal boron nitride (h-BN) is known as promising 2D material with a wide band-gap (~6 eV). However, the growth size of h-BN film is strongly limited by the size of reaction chamber. Here, we demonstrate the large-roll synthesis of monolayer and controllable sub-monolayer h-BN film on wound Cu foil by low pressure chemical vapor deposition (LPCVD) method. By winding the Cu foil substrate into mainspring shape supported by a multi-prong quartz fork, the reactor size limit could be overcome by extending the substrate area to a continuous 2D curl of plane inward. An extremely large-size monolayer h-BN film has been achieved over 25 inches in a 1.2" tube. The optical band gap of h-BN monolayer was determined to be 6.0 eV. The h-BN film was uniformly transferred onto 2" GaN or 4" Si wafer surfaces as a release buffer layer. By HVPE method, overgrowth of thick GaN wafer over 200 μm has been achieved free of residual strain, which could provide high quality homo-epitaxial substrate.
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Chenping
authors.initials: C
authors.lastname: Wu
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Abdul Majid
authors.initials: AM
authors.lastname: Soomro
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Feipeng
authors.initials: F
authors.lastname: Sun
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Huachun
authors.initials: H
authors.lastname: Wang
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Youyang
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Research Center for Wide-gap Semiconductors, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
authors.forename: Jiejun
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yang
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Na
authors.initials: N
authors.lastname: Gao
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
authors.forename: Junyong
authors.initials: J
authors.lastname: Kang
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, CI center for OSED, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.|Department of Chemistry, Duke University, Durham, NC 27708-0354, USA.
authors.forename: Duanjun
authors.initials: D
authors.lastname: Cai