Synthesis of Atomically Thin Boron Films on Copper Foils.
Two-dimensional boron materials have recently attracted extensive theoretical interest because of their exceptional structural complexity and remarkable physical and chemical properties. However, such 2D boron monolayers have still not been synthesized. In this report, the synthesis of atomically thin 2D γ-boron films on copper foils is achieved by chemical vapor deposition using a mixture of pure boron and boron oxide powders as the boron source and hydrogen gas as the carrier gas. Strikingly, the optical band gap of the boron film was measured to be around 2.25 eV, which is close to the value (2.07 eV) determined by first-principles calculations, suggesting that the γ-B28 monolayer is a fascinating direct band gap semiconductor. Furthermore, a strong photoluminescence emission band was observed at approximately 626 nm, which is again due to the direct band gap. This study could pave the way for applications of two-dimensional boron materials in electronic and photonic devices.
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China). taiguoan@nuaa.edu.cn.
Guoan
G
Tai
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).|School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Tingsong
T
Hu
School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China).
Yungang
Y
Zhou
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).|School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Xufeng
X
Wang
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).|College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Jizhou
J
Kong
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).|School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Tian
T
Zeng
School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Yuncheng
Y
You
School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China).
Qin
Q
Wang
boron; chemical vapor deposition; direct band gaps; monolayers; thin films