论文标题
来自局部修改的Becke-Johnson电位的二维材料的精确电子带隙
Accurate electronic band gaps of two-dimensional materials from the local modified Becke-Johnson potential
论文作者
论文摘要
由于量子限制和电子筛选的强烈修改，二维材料的电子带结构与它们的散装材料的电子带结构显着不同。电子状态的准确确定是设计二维材料的电子或光电应用的先决条件，但是，我们可用于计算带隙的大多数理论方法不准确，计算价格昂贵，或者仅适用于散装系统。在这里，我们表明，使用密度功能理论可以通过我们最近提出的局部修改的BECKE-JOHNSON交换与相关功能来有效地计算纳米结构系统的可靠带结构。在对二维材料专门为二维材料的该功能的参数重新提高后，我们显示，对于近300个系统的测试集，获得的带隙与使用最佳混合功能获得的质量相当，但计算成本非常降低。这些结果为对二维材料的带结构以及具有大型单位细胞的范德华异质结构进行精确的高通量研究开辟了道路。
The electronic band structures of two-dimensional materials are significantly different from those of their bulk counterparts, due to quantum confinement and strong modifications of electronic screening. An accurate determination of electronic states is a prerequisite to design electronic or optoelectronic applications of two-dimensional materials, however, most of the theoretical methods we have available to compute band gaps are either inaccurate, computationally expensive, or only applicable to bulk systems. Here we show that reliable band structures of nanostructured systems can now be efficiently calculated using density-functional theory with the local modified Becke-Johnson exchange-correlation functional that we recently proposed. After re-optimizing the parameters of this functional specifically for two-dimensional materials, we show, for a test set of almost 300 systems, that the obtained band gaps are of comparable quality as those obtained using the best hybrid functionals, but at a very reduced computational cost. These results open the way for accurate high-throughput studies of band-structures of two-dimensional materials and for the study of van der Waals heterostructures with large unit cells.
