Ozturk Birol, de-Luna-Bugallo Andres, Panaitescu Eugen, Chiaramonti Ann N, Liu Fangze, Vargas Anthony, Jiang Xueping, Kharche Neerav, Yavuzcetin Ozgur, Alnaji Majed, Ford Matthew J, Lok Jay, Zhao Yongyi, King Nicholas, Dhar Nibir K, Dubey Madan, Nayak Saroj K, Sridhar Srinivas, Kar Swastik
Department of Physics, Northeastern University, Boston, MA 02115, USA. ; Electronic Materials Research Institute, Northeastern University, Boston, MA 02115, USA. ; Department of Physics and Engineering Physics, Morgan State University, Baltimore, MD 21251, USA.
Department of Physics, Northeastern University, Boston, MA 02115, USA. ; Cinvestav Unidad Querétaro, Querétaro, Qro. 76230, Mexico.
Sci Adv. 2015 Jul 31;1(6):e1500094. doi: 10.1126/sciadv.1500094. eCollection 2015 Jul.
In recent times, atomically thin alloys of boron, nitrogen, and carbon have generated significant excitement as a composition-tunable two-dimensional (2D) material that demonstrates rich physics as well as application potentials. The possibility of tunably incorporating oxygen, a group VI element, into the honeycomb sp(2)-type 2D-BNC lattice is an intriguing idea from both fundamental and applied perspectives. We present the first report on an atomically thin quaternary alloy of boron, nitrogen, carbon, and oxygen (2D-BNCO). Our experiments suggest, and density functional theory (DFT) calculations corroborate, stable configurations of a honeycomb 2D-BNCO lattice. We observe micrometer-scale 2D-BNCO domains within a graphene-rich 2D-BNC matrix, and are able to control the area coverage and relative composition of these domains by varying the oxygen content in the growth setup. Macroscopic samples comprising 2D-BNCO domains in a graphene-rich 2D-BNC matrix show graphene-like gate-modulated electronic transport with mobility exceeding 500 cm(2) V(-1) s(-1), and Arrhenius-like activated temperature dependence. Spin-polarized DFT calculations for nanoscale 2D-BNCO patches predict magnetic ground states originating from the B atoms closest to the O atoms and sizable (0.6 eV < E g < 0.8 eV) band gaps in their density of states. These results suggest that 2D-BNCO with novel electronic and magnetic properties have great potential for nanoelectronics and spintronic applications in an atomically thin platform.
近年来，硼、氮和碳的原子级薄合金作为一种成分可调的二维（2D）材料引起了极大关注，这种材料展现出丰富的物理特性以及应用潜力。从基础和应用的角度来看，将第VI族元素氧可调谐地掺入蜂窝状sp(2)型二维氮化硼碳（2D-BNC）晶格中是一个引人入胜的想法。我们首次报道了硼、氮、碳和氧的原子级薄四元合金（2D-BNCO）。我们的实验表明，并且密度泛函理论（DFT）计算也证实，存在蜂窝状二维氮化硼碳氧（2D-BNCO）晶格的稳定构型。我们在富含石墨烯的二维氮化硼碳（2D-BNC）基质中观察到微米级的二维氮化硼碳氧（2D-BNCO）畴，并且能够通过改变生长装置中的氧含量来控制这些畴的面积覆盖率和相对组成。在富含石墨烯的二维氮化硼碳（2D-BNC）基质中包含二维氮化硼碳氧（2D-BNCO）畴的宏观样品显示出类似石墨烯的栅极调制电子输运，迁移率超过500 cm(2) V(-1) s(-1)，并且具有类似阿仑尼乌斯的激活温度依赖性。对纳米级二维氮化硼碳氧（2D-BNCO）薄片的自旋极化DFT计算预测，其磁基态源自最靠近氧原子的硼原子，并且在其态密度中存在相当大的（0.6 eV < E g < 0.8 eV）带隙。这些结果表明，具有新颖电子和磁性特性的二维氮化硼碳氧（2D-BNCO）在原子级薄平台上的纳米电子学和自旋电子学应用中具有巨大潜力。
