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arXiv 2106.07090cond-mat.mtrl-sci
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直接带隙半导体类石墨烯的超高热导率和强度BC6N:第一性原理和经典研究

Ultrahigh thermal conductivity and strength in direct-gap semiconducting graphene-like BC6N: A first-principles and classical investigation

Bohayra Mortazavi

摘要:

近年来,石墨烯类碳化硼和氮化碳纳米片由于其半导体电子性质和优异的机械和热传输性能而引起了人们的广泛关注。类石墨烯BC6N是一种实验实现的层状材料,最近一直是许多理论研究的焦点。有趣的是,BC6N单层的最稳定形式仍未被探索,并且关于其固有物理性质的信息有限。在此,密度泛函理论(DFT)计算的基础上,我们确认,最稳定的形式的BC6N纳米片显示了一个矩形的unitcell,根据一个被忽视的实验发现。我们发现BC_6N单层膜是一种直接带隙为1.19 eV的半导体,具有各向异性和良好的可见光吸收。第一性原理的结果强调,BC6N纳米片表现出各向异性和可调的拉伸强度和晶格热导率,优于所有其他制造的2D半导体。此外,我们开发经典的分子动力学模型的热传输和力学性能的BC6N纳米膜的评价。这项工作中所呈现的结果不仅揭示了BC6N纳米片的最稳定构型,而且还证实了其出色的吸引人的电子,光学,热传导和机械性能,极大地激励了进一步的理论和实验努力。

英文摘要:

In recent years, graphene-like boron carbide and carbon nitride nanosheets have attracted remarkable attentions, owing to their semiconducting electronic nature and outstanding mechanical and heat transport properties. Graphene-like BC6N is an experimentally realized layered material and most recently has been the focus of numerous theoretical studies. Interestingly, the most stable form of BC6N monolayer remains unexplored and limited information are known concerning its intrinsic physical properties. Herein, on the basis of density functional theory (DFT) calculations we confirm that the most stable form of BC6N nanosheet shows a rectangular unitcell, in accordance with an overlooked experimental finding. We found that BC6N monolayer is a semiconductor with 1.19 eV direct gap and yields anisotropic and excellent absorption of visible light. First-principles results highlight that BC6N nanosheet exhibits anisotropic and ultrahigh tensile strength and lattice thermal conductivity, outperforming all other fabricated 2D semiconductors. We moreover develop classical molecular dynamic models for the evaluation of heat transport and mechanical properties of BC6N nanomembranes. The presented results in this work not only shed light on the most stable configuration of BC6N nanosheet, but also confirm its outstandingly appealing electronic, optical, heat conduction and mechanical properties, extremely motivating for further theoretical and experimental endeavors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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