单层黑磷和蓝磷扩展分子结的电子输运特性

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-V curve disappear gradually, which leads to the emergence of the characteristic similar to metal in I-V curve. 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.