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arXiv 1605.09581cond-mat.mtrl-sci
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氮化硼单层中的激子

Excitons in boron nitride single layer

Thomas Galvani, Fulvio Paleari, Henrique Miranda, Alejandro Molina-Sánchez, Ludger Wirtz, Sylvain Latil, Hakim Amara, François Ducastelle

摘要:

氮化硼单层属于二维材料家族,其光学性质目前受到相当大的关注。强烈的激子效应已经被观察到的散装和更强的影响,预测单层。在这里,我们提出了一个详细的研究,这些属性相结合的\textit{ab initio}计算和紧束缚Wannier分析在实空间和倒易空间。由于简单的能带结构与单价($π$)和导电($π^*$)带的紧束缚分析成为准定量只有两个可调参数,并提供了工具的激子特性的详细分析。强烈偏离通常的氢模型的证据。基态激子不是真正的Frenkel激子,而是一种非常局域化的“紧束缚”激子。其他的类似于在过渡金属二硫属化物中发现的那些,虽然更局部化,但可以在Wannier-Mott方案中描述。

英文摘要:

Boron nitride single layer belongs to the family of 2D materials whose optical properties are currently receiving considerable attention. Strong excitonic effects have already been observed in the bulk and still stronger effects are predicted for single layers. We present here a detailed study of these properties by combining \textit{ab initio} calculations and a tight-binding-Wannier analysis in both real and reciprocal space. Due to the simplicity of the band structure with single valence ($π$) and conduction ($π^*$) bands the tight-binding analysis becomes quasi quantitative with only two adjustable parameters and provides tools for a detailed analysis of the exciton properties. Strong deviations from the usual hydrogenic model are evidenced. The ground state exciton is not a genuine Frenkel exciton, but a very localized "tightly-bound" one. The other ones are similar to those found in transition metal dichalcogenides and, although more localized, can be described within a Wannier-Mott scheme.

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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