Di Maoyun, Fu Lin, Wang Yong, Zhang Kaiyu, Xu Yongjie, Pan Hongzhe, Du Youwei, Tang Nujiang
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University Nanjing 210093 China
School of Physics and Electronic Engineering, Linyi University Linyi 276005 China
RSC Adv. 2019 Oct 31;9(60):35297-35303. doi: 10.1039/c9ra07869j. eCollection 2019 Oct 28.
The upsurge in the research of α-graphyne (α-GY) has occurred due to the existence of a Dirac cone, whereas the absence of band gap impedes its semiconductor applications. Here, the electronic properties of α-GY on hexagonal boron nitride (h-BN) and α-BNyne (α-BNy) monolayers are investigated using first-principles calculations. Through engineering heterostructures, the band gap opening can be achieved and has different responses to the substrate and stacking sequence. Intriguingly, the band gap of α-GY/α-BNy with Ab1 stacking mode is up to 77.5 meV in the HSE06 functional, which is distinctly greater than at room temperature. The characteristic Dirac band of α-GY is preserved on the α-BNy substrate, while it changes into a parabolic band on the h-BN substrate. Additionally, we also find that changing the interlayer distance is an alternative strategy to realize the tunable band gap. Our results show that by selecting a reasonable substrate, the linear band structure and thus the high carrier mobility as well as the distinct band gap opening could coexist in α-GY. These prominent properties are the key quantity for application of α-GY in nanoelectronic devices.
由于狄拉克锥的存在，α-石墨炔（α-GY）的研究热潮兴起，然而其带隙的缺失阻碍了它在半导体领域的应用。在此，我们利用第一性原理计算研究了α-GY在六方氮化硼（h-BN）和α-硼炔（α-BNy）单层上的电子性质。通过构建异质结构，可以实现带隙的打开，并且对衬底和堆叠顺序有不同的响应。有趣的是，在HSE06泛函中，具有Ab1堆叠模式的α-GY/α-BNy的带隙高达77.5毫电子伏特，这在室温下明显大于……。α-GY的特征狄拉克带在α-BNy衬底上得以保留，而在h-BN衬底上则转变为抛物线形能带。此外，我们还发现改变层间距离是实现可调带隙的另一种策略。我们的结果表明，通过选择合理的衬底，α-GY中线性能带结构以及高载流子迁移率和明显的带隙打开可以共存。这些突出的性质是α-GY在纳米电子器件中应用的关键因素。
