▎ 摘　　要

Based on the density functional theory and the non-equilibrium Green's function method, the electronic transport properties of zigzag-edged triangular graphene were studied systematically. The results revealed that the current voltage (I-V) characteristics and rectifying effects were closely related to the geometric size and the type of atoms terminated at the edges of triangular graphene. In the case of Hand S-terminated edges, a small triangular graphene had a large current but with a small rectifying ratio. Although the current increased, the rectifying behavior was lowered when H atoms at the edges of the structure were replaced by O atoms. Deeper analysis demonstrated that such a rectification was caused by the asymmetry in the spatial distribution of the frontier orbitals and an asymmetric movement on the molecular-level in triangular graphene under positive and negative biases. It is of great significance that our investigations develop a thorough understanding of the basic physical properties of a triangular graphene.