掺P石墨烯结构和电子性质的第一性原理研究

First Principles Study on the Structure and Electronic Properties of P Doped Graphene

基于密度泛函理论第一性原理,在广义梯度近似下,本文研究本征石墨烯和掺杂不同浓度P的石墨烯结构和电子性质并发现本征石墨烯禁带宽度为零;对于P∶C掺杂比分别为1∶17、1∶7、1∶1的石墨烯,其P-C键长由0.142nm的C-C键分别增大为0.1629 nm、0.1625 nm、0.1751 nm,其对应带隙分别由零带隙变为0.28 eV、0.44 eV、1.21eV:费米能级逐渐下降。分析分波态密度后发现,在掺P石墨烯中主要为P原子的3p态电子影响其总态密度。

Using the first-principles method based on the density functional theory （DbT）, the structures and electronic properties of the intrinsic and phosphorus （P） doped graphene were calculated with the generalized gradient approximation. The results show that the band gap of the intrinsic graphene is zero. The length of C-C bond for intrinsic graphene is 0. 142 nm. The length of P-C bond are 0. 1629 nm, 0. 1625 nm, 0. 1751 nm, which are respective to the different P： C ratio for 1： 17, 1：7 and 1： 1. Band gap is increased from zero to 0.28 eV, 0.44 eV, 1.21 eV, and the Fermi level is gradually decreased with increasing the doping concentration. The analysis of the partial densities of states （PDOS） indicates that 3p electrons of P atom affect total density of states.