Bu Hongxia, Zheng Haibin, Zhang Hongyu, Yuan Huimin, Zhao Jingfen
College of Physics and Electronic Engineering, Qilu Normal University, Jinan, Shandong, 250200, China.
Department of Physics, East China University of Science and Technology, Shanghai, 200237, China.
Sci Rep. 2020 Apr 22;10(1):6808. doi: 10.1038/s41598-020-63693-2.
We investigated the optical properties and roles of sp- and sp-hybridized bonds of a hexagonal C/BN family using first-principles calculations. The calculated phonon dispersions confirm the dynamic stability of Hex-(BN)C and Hex-C(BN). The complex dielectric function evolves from the infrared to the ultraviolet region and has a significant anisotropy for different polarizations. The reflectivity and refractive index spectra show that the sp-hybridized C atoms are more sensitive to the light from infrared to visible region than B-N pairs while the C atoms and B-N pairs have a similar sensitivity to high frequencies. The sharp peaks of the energy-loss spectrum are all concentrated in the 23-30 eV energy region, which can be used to identify these hexagonal structures. The calculated band structures show Hex-C and Hex-(BN)C are metals, but Hex-C(BN) and Hex-(BN) are semiconductors with indirect band gaps of 3.47 and 3.25 eV, respectively. The electronic states near the Fermi level primarily originate from sp-hybridized atoms. In addition, sp-hybridized bonds are the main elements affecting the optical and electronic structure of C/BN materials with sp- and sp-hybridizations. We expect that the results presented will help understand the optical properties of C/BN materials containing sp- and sp-hybridized C atoms and B-N pairs.
我们使用第一性原理计算研究了六方C/BN族中sp和sp杂化键的光学性质及其作用。计算得到的声子色散证实了Hex-(BN)C和Hex-C(BN)的动力学稳定性。复介电函数从红外区域演变到紫外区域，并且对于不同偏振具有显著的各向异性。反射率和折射率光谱表明，从红外到可见光区域，sp杂化的C原子比B-N对 对光更敏感，而C原子和B-N对 对高频光具有相似的敏感性。能量损失谱的尖锐峰都集中在23-30 eV能量区域，这可用于识别这些六方结构。计算得到的能带结构表明Hex-C和Hex-(BN)C是金属，但Hex-C(BN)和Hex-(BN)是半导体，其间接带隙分别为3.47和3.25 eV。费米能级附近的电子态主要起源于sp杂化原子。此外，sp杂化键是影响具有sp和sp杂化的C/BN材料光学和电子结构的主要因素。我们期望所呈现的结果将有助于理解含有sp和sp杂化的C原子及B-N对 的C/BN材料的光学性质。
