【摘要】 采用基于密度泛函理论的第一性原理计算,研究了铝掺杂对单壁扶手型(6,6)硅纳米管电子结构和光电性质的影响。结果表明,本征态硅纳米管属于直接带隙半导体,其禁带宽度为0.42eV,而铝掺杂硅纳米管为间接带隙半导体,其禁带宽度为0.02eV。单壁扶手型(6,6)硅纳米管的价带顶主要由Si-3p态电子构成,而其导带底则主要由Si-3p态电子决定。同时通过铝掺杂,使硅纳米管的禁带宽度变窄,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。更多还原

【Abstract】 The effects of Al doping on the electronic structure and photoelectric properties of single-walled armchair(6,6)silicon nanotubes were determined by first-principles calculations in the framework of density-functional theory.The results indicated that the pure silicon nanotubes presented a direct band gap of 0.42 eV,whereas the Aldoped silicon nanotubes presented an indirect band gap of 0.02 eV.The top of valence band was fundamentally determined by the Si-3p states and the bottom of conduction band was primarily occupied by the Si-3p states in the singlewalled armchair(6,6)silicon nanotubes.Moreover,the band gap of single-walled armchair(6,6)silicon nanotubes was decreased and the optical absorption was red-shifted with Al doping.The results provide useful theoretical guidance for the applications of silicon nanotubes in optical detectors.更多还原