单层黑磷和蓝磷扩展分子结的电子输运特性  

Electron Transport Properties of Monolayer Black Phosphorus and Blue Phosphorus Molecular Junctions

作　　者：孙豆豆 苏文勇[1] SUN Doudou;SU Wenyong(School of Physics,Beijing Institute of Technology,Beijing 100081)

机构地区：[1]北京理工大学物理学院,北京100081

出　　处：《材料导报》2018年第12期2105-2111,2128,共8页Materials Reports

基　　金：国家自然科学基金(11374033)

摘　　要：本工作应用非平衡格林函数理论和密度泛函理论研究了二维材料单层黑磷扩展分子结和蓝磷扩展分子结的电子输运特性,以及在应力作用下能隙和伏安特性的变化特点。结果发现,两种扩展分子结在发生应变(拉伸和压缩)过程中,随着应变(拉伸和压缩)的增加,HOMO能量和LUMO能量逐步靠近,导致能隙逐渐降低,分别减小了0.67eV和1.33eV。能隙降低,同时导通轨道间隔和导通轨道迁移率也降低,导致伏安特性曲线中量子化台阶逐渐消失,出现了类似金属的I-V曲线特点。此外,单层黑磷扩展分子结在0.75~2.00V范围内产生稳定电流,有望应用于电路中的稳流装置。Nonequilibrium green function theory（NGFT）and density functional theory（DFT）were performed to investigate the electronic-transport properties and the effects of strain on energy gaps and current-voltage characteristics of 2D materials monolayer black phosphorus and blue phosphorus molecular junctions.We find that the highest occupied molecular orbital（HOMO）and the lowest unoccupied molecular orbital（LUMO）close to each other with the increase of strain（tension or compression）gradually,which result in the energy gaps of black phosphorus and blue phosphorus molecular junctions decrease by 0.67 eV and 1.33 eV,respectively.The reduction of energy gap,the diminution of the interval of conduction orbits and the decrease of conduction orbital mobility cause the quantized steps of I-Vcurve disappear gradually,which leads to the emergence of the characteristic similar to metal in I-Vcurve.Moreover,the monolayer black phosphorus molecular junction produces a stable current in the range of 0.75—2.00 V,which is expected to act as the stabilizer of circuits.

关 键 词：黑磷 蓝磷 扩展分子结 电子输运 能隙 

分 类 号：O469[理学—凝聚态物理]