三维BN分子及P/Al替代其sp^3键合原子的电子输运特性

Electronic Transport Properties for the Molecules Junctions of the Three-Dimensional BN and Their sp^3 Bonded Atoms Substituted by P or Al Atom

利用P和Al替代三维BN分子的sp3键合原子,再通过S原子与金电极相连组成三明治结构的分子器件,并对三维BN分子及替换形成的分子器件的电子输运特性进行了模拟计算.计算结果显示:三维B6N5正和负偏压下均显示出分子开关效应.当其中心N原子(sp3键合原子)被P替代后,隧穿电流变化明显,且整个偏压区内不再具有对称性;三维B5N6的电流-电压曲线上显示出明显的负微分电阻现象,而当其中心B原子被Al替代后,电流-电压基本特性没有发生变化,只是电流有了显著的减小.

The sp^3 bonded atoms of the three-dimensional BN molecule were substituted by P or Al, then the molecule junctions were sandwiched between two gold electrodes and S atoms. The electronic transport properties for molecule junctions and the sandwich structures were investigated. The results revealed that the three-dimensional B6N5 junction demonstrated obvious switch effect in both positive and negative bias range. When the N atom in the center （sp^3 bonded atom） of B6N5 was substituted by P ,the tunneling current changed obviously and the I-V curve was asymmetrical in the whole bias range. A significant negative differential resistance behavior was also observed from the I-V curve of the three-dimensional B5 N6 molecule junction. However, when the B atom in the center of B5N6was substituted by Al, the basic I-V characteristics had no change except that the current decreased remarkably.