Tang Qing, Bao Jie, Li Yafei, Zhou Zhen, Chen Zhongfang
Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Computational Centre for Molecular Science, Institute of New Energy Material Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, PR China.
Nanoscale. 2014 Aug 7;6(15):8624-34. doi: 10.1039/c4nr00008k.
Density functional theory computations with dispersion corrections (DFT-D) were performed to investigate the dihalogen interactions and their effect on the electronic band structures of halogenated (fluorinated and chlorinated) BN bilayers and aligned halogen-passivated zigzag BN nanoribbons (BNNRs). Our results reveal the presence of considerable homo-halogen (FF and ClCl) interactions in bilayer fluoro (chloro)-BN sheets and the aligned F (Cl)-ZBNNRs, as well as substantial hetero-halogen (FCl) interactions in hybrid fluoro-BN/chloro-BN bilayer and F-Cl-ZBNNRs. The existence of interfacial dihalogen interactions leads to significant band-gap modifications for the studied BN nanosystems. Compared with the individual fluoro (chloro)-BN monolayers or pristine BNNRs, the gap reduction in bilayer fluoro-BN (B-FF-N array), hybrid fluoro-BN/chloro-BN bilayer (N-FCl-N array), aligned Cl-ZBNNRs (B-ClCl-N alignment), and hybrid F-Cl-ZBNNRs (B-FCl-N alignment) is mainly due to interfacial polarizations, while the gap narrowing in bilayer chloro-BN (N-ClCl-N array) is ascribed to the interfacial nearly-free-electron states. Moreover, the binding strengths and electronic properties of the interactive BN nanosheets and nanoribbons can be controlled by applying an external electric field, and extensive modulation from large-gap to medium-gap semiconductors, or even metals can be realized by adjusting the direction and strength of the applied electric field. This interesting strategy for band gap control based on weak interactions offers unique opportunities for developing BN nanoscale electronic devices.
进行了含色散校正的密度泛函理论计算（DFT-D），以研究二卤相互作用及其对卤化（氟化和氯化）BN双层以及对齐的卤化钝化锯齿形BN纳米带（BNNRs）电子能带结构的影响。我们的结果表明，在双层氟（氯）化BN片材和对齐的F（Cl）-ZBNNRs中存在相当可观的同卤（FF和ClCl）相互作用，以及在混合氟-硼/氯-硼双层和F-Cl-ZBNNRs中存在大量的异卤（FCl）相互作用。界面二卤相互作用的存在导致所研究的BN纳米系统的能带隙发生显著变化。与单个氟（氯）化BN单层或原始BNNRs相比，双层氟-硼（B-FF-N阵列）、混合氟-硼/氯-硼双层（N-FCl-N阵列）、对齐的Cl-ZBNNRs（B-ClCl-N排列）和混合F-Cl-ZBNNRs（B-FCl-N排列）中的能隙减小主要归因于界面极化，而双层氯-硼（N-ClCl-N阵列）中的能隙变窄归因于界面近自由电子态。此外，通过施加外部电场可以控制相互作用的BN纳米片和纳米带的结合强度和电子性质，并且通过调整所施加电场的方向和强度，可以实现从大带隙到中带隙半导体甚至金属的广泛调制。这种基于弱相互作用的有趣的带隙控制策略为开发BN纳米级电子器件提供了独特的机会。
