Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Nanoscale. 2013 Jul 21;5(14):6381-7. doi: 10.1039/c3nr01180a. Epub 2013 Jun 4.
Using hybrid density functional theory calculations with van der Waals correction, we show that polar boron nitride (BN) nanoribbons can be favorably aligned via substantial hydrogen bonding at the interfaces, which induces significant interface polarizations and sharply reduces the band gap of insulating ribbons well below the silicon range. The interface polarization can strongly couple with carrier doping or applied electric fields, yielding not only enhanced stability but also widely tunable band gap for the aligned ribbons. Furthermore, similar layer-by-layer alignment also effectively reduces the band gap of a 2D hydrogenated BN sheet and even turns it into metal. This novel strategy for band gap control appears to be general in semiconducting composite nanostructures with polar nonbonding interfaces and thus offers unique opportunities for developing nanoscale electronic and optical devices.
利用含范德华力修正的杂化密度泛函理论计算，我们表明，通过界面处大量氢键作用，极性氮化硼（BN）纳米带可以有利地排列，这会引起显著的界面极化，并将绝缘带的带隙大大降低至低于硅的范围。界面极化可以与载流子掺杂或外加电场强烈耦合，不仅产生增强的稳定性，而且还为对齐的纳米带提供广泛可调的带隙。此外，类似的逐层排列还可以有效地降低二维氢化 BN 片的带隙，甚至将其转变为金属。这种用于控制带隙的新策略在具有非键合界面的半导体复合材料纳米结构中似乎是通用的，因此为开发纳米尺度的电子和光学器件提供了独特的机会。
