In this contribution, electronic structures and optical properties of pure and doped single-walled carbon nanotubes (SWCNTs) are investigated by the first-principles calculation. It is found that the B- and N-doped systems have the lowest binding energies of −31.41eV and −30.97eV, respectively, indicating that the configurations are relatively stable. Interestingly, the indirect bandgap is transforming into a direct bandgap in the two systems, which has a good development prospect in the field of light-emitting devices. The charge difference density diagrams show that the electron deletion around all doped atoms is weakened, indicating that the covalence between the doped atom and carbon atom is weakened, which is consistent with the population analysis result. In the absorption spectrum, there is a “blueshift” phenomenon. In the reflection spectrum, the six doping systems show an obvious “redshift” phenomenon. In addition, the polarization ability of all doping systems has become stronger. Also, due to the different changes in the peak values of the imaginary part of the dielectric function, the doping of Al, Ga and P improved the photoresponse of the low-energy region, while the doping of B, N and As weakens it.

中文翻译：

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从第一性原理研究掺杂单壁碳纳米管的电子特性和光学特性

在这项贡献中，通过第一性原理计算研究了纯和掺杂单壁碳纳米管 (SWCNT) 的电子结构和光学性质。发现 B 和 N 掺杂系统具有最低的结合能-31.41eV 和-30.97eV 分别表示配置相对稳定。有趣的是，间接带隙在两个体系中正在向直接带隙转变，在发光器件领域具有良好的发展前景。电荷差密度图显示，所有掺杂原子周围的电子缺失减弱，表明掺杂原子与碳原子的共价键减弱，与布居分析结果一致。在吸收光谱中，存在“蓝移”现象。在反射光谱中，六种掺杂体系均表现出明显的“红移”现象。此外，所有掺杂体系的极化能力都变得更强。此外，由于介电函数虚部峰值的不同变化，Al的掺杂，