P掺杂硅纳米管电子结构与光学性质的研究

采用基于密度泛函理论的第一性原理计算,研究了P掺杂对单壁扶手型硅纳米管电子结构和光学性质的影响.结果表明:经过P掺杂,单壁扶手型硅纳米管的能带结构从间接带隙变为直接带隙,其价带顶主要由Si-3p态电子构成,导带底主要由Si-3p态电子和Si-3s态电子共同决定;同时通过P掺杂,使单壁扶手型硅纳米管的禁带宽度变窄,导电性增强,吸收光谱产生红移.研究结果为硅纳米管在光电器件方面的应用提供了理论基础.

The electronic structure and optical properties of P-doped silicon nanotubes

We perform first-principles calculations in the framework of density-functional theory to determine the effects of P doping on the electronic structure and optical properties of single-walled armchair silicon nanotubes. The calculated results indicate that the band-gap of single-walled armchair silicon nanotubes changes from indirect to direct one, with the P element doped. The top of valence band is determined mainly by the Si-3p electrons, and the bottom of conduction band is occupied by the Si-3p electrons and Si-3s electrons. Moreover, the band gap of single-walled armchair silicon nanotubes decreases and the optical absorption is red-shifted, with the P element doped. The results provide useful theoretical guidance for the applications of silicon nanotubes in optical detectors.
Keywords： first-principles silicon nanotubes electronic structure optical properties