金电极下二元化合物氮化镓链结构演化和电导的从头计算

基于从头密度泛函理论结合非平衡格林函数方法，首次研究了二元化合物GaN链介于两个金电极之间的电子输运性质。模拟了Au-(GaN)2-Au节点断裂过程，计算了相应的结合能，获得了平衡态电导以及平衡态下节点的投影态密度。此外，计算了平衡态下节点在微小偏压下的电流和电导。结果发现，随着偏压增强，GaN分子链的电导也随之下降。最后给出的伏安特性曲线呈现一个非线性关系，表明节点具有类似半导体的特征。

Ab Initio Calculations of Structural Evolution and Conductance of Binary Compound GaN Chain on Gold Leads

By performing ab inito density functional theory plus the non-equilibrium Green''s function method, we investigate the electron transport properties of binary GaN molecular chain sandwiched between the Au electrodes for the first time. We simulate the Au-(GaN)2-Au junctions breaking process, calculate the corresponding cohesion energy, obtain the equilibrium conductance and the projected density of states of junctions in the optimal position. In additional, both the current and conductance of junctions at the optimal position are computed under small bias. It is found that, with the increase of the bias voltage, the conductance of the GaN molecular chain always decreases. The I-V curve displays a non-linear relationship, indicating that the junctions have a semiconductor-like characteristic.