Shen Yang, Yang Xiaodong, Bian Yue, Nie Kuiying, Liu Songmin, Tang Kun, Zhang Rong, Zheng Youdou, Gu Shulin
School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics, Nanjing University, Nanjing, 210093, China.
Sci Rep. 2018 Oct 18;8(1):15464. doi: 10.1038/s41598-018-33991-x.
In recent years, various kinds of ZnO-based core@shell nanomaterials have been paid much attention due to their widespread applications in the fields of physics, chemistry and energy conversion. In this work, the electronic and optical properties of a new type of ZnO-based one-dimensional core@shell nanostructure, which is composed of inner ZnO nanowire and outer carbon nanotube (CNT), is calculated based on the first-principles density functional theory (DFT). Calculation results suggest that the ZnO nanowire encapsulated in (9, 9)-CNT is the most stable structure from the view of formation energy. The interaction between the inner ZnO nanowire and the outer (9, 9) CNT belongs to a weak van der Waals type. The complex structure is found to possess metallicity for the outer (9, 9) CNT and maintain the wide band gap nature for the inner ZnO nanowire. Under the different external strains, the charge redistribution between inner ZnO nanowire and outer CNT caused by electron tunneling leads to the shift of Dirac point and the band narrowing of inner ZnO nanowire. The inner ZnO nanowire only has light absorption in the UV region, which is consistent with its optical property originating from its wide bandgap nature.
近年来，各种基于氧化锌的核壳纳米材料因其在物理、化学和能量转换领域的广泛应用而备受关注。在这项工作中，基于第一性原理密度泛函理论（DFT）计算了一种新型的基于氧化锌的一维核壳纳米结构的电子和光学性质，该结构由内部的氧化锌纳米线和外部的碳纳米管（CNT）组成。计算结果表明，从形成能的角度来看，封装在（9,9）-碳纳米管中的氧化锌纳米线是最稳定的结构。内部氧化锌纳米线与外部（9,9）碳纳米管之间的相互作用属于弱范德华类型。发现该复合结构对于外部（9,9）碳纳米管具有金属性，而内部氧化锌纳米线保持宽带隙性质。在不同的外部应变下，由电子隧穿引起的内部氧化锌纳米线和外部碳纳米管之间的电荷重新分布导致狄拉克点的移动和内部氧化锌纳米线的能带变窄。内部氧化锌纳米线仅在紫外区域有光吸收，这与其源于宽带隙性质的光学性质一致。
