拉伸形变下BC3纳米管的能带结构

运用紧束缚能带理论，研究拉伸形变下BC₃纳米管的能带结构. 研究表明:随着拉伸和压缩强度的不断增加,BC₃纳米管的导带能级和价带能级逐渐靠近，最终发生能带交叠. 压缩形变下能带的交叠程度可达05 eV，而拉伸形变下只有02 eV. 对于扶手椅型BC₃纳米管，随着拉伸和压缩的不断增加，BC₃纳米管首先由直接半导体转化为间接半导体，进而发生能带的交叠，表现出金属性. 在无形变时，扶手椅型BC₃纳米关键词：3纳米管')" href="#">BC₃纳米管能隙拉伸形变半导体

Band structures of strain-deformed BC3 nanotubes

By using the tight-binding energy band theory, we study the band structures of BC₃ nanotubes under stretching and compressing deformations, the conductivity band turns more and more close to the valence band of the BC₃ nanotubes and eventually they overlap each other with the increase of tension. Furthermore, the results obtained show that the overlap under compressing is bigger than that under stretching. The biggest overlap under compressing is up to 0.5 eV, but it is only 0.2 eV under stretching. In addition, for armchair BC₃ nanotubes, the results of band structures show that with the increase of tension, the BC₃ nanotube transforms into an indirect semiconductor from a direct semiconductor, and then leads to the band overlap. The armchair BC₃ nanotube is an unstable narrow-gap semiconductor, because a little compress (e _t= -0.003) can convert it transform into an indirect semiconductor from a direct semiconductor. For zigzag BC₃ nanotubes, a slight deformation can turn into a direct semiconductor having only one allowed wave vector from a direct semiconductor having all wave vectors, owing to the existence of two flat conductivity and valence bands.