二维B-C-N材料的电子结构和光学性质的快速GW计算

二维层状材料以其极薄的尺寸和优异的性能受到了研究者的广泛关注。通过掺杂和层间范德华相互作用来调控二维材料的性质一直是研究热点之一。近来发现通过硼-氮掺杂石墨烯所构成的新型二维硼碳氮结构，如C3N和C3B等，展现出非常丰富的物理性质。然而目前人们对其他二维硼碳氮材料的结构及其性质尚不清楚。针对该科学问题，本项目拟通过理论设计不同构型的二维B-C-N晶体结构，使得这些体系所展现出来的本征带隙在很宽范围内连续可调，并研究其在不同堆叠条件下莫尔结构的新奇物性。本项目不仅利用第一性原理密度泛函理论进行模拟相关电子结构和光学性质，而且用我们最近发展的快速GW计算方法来研究新型二维硼碳氮结构的准粒子性质及其激子效应。通过本项目的实施，有望对二维硼碳氮的光电性能进行精准预测并掌握调控其性质的方法，进而为实验合成和性能设计提供理论支撑，所以本项目具有重要的现实意义。

Two-dimensional (2D) layered materials have attracted lots of researchers’ attention due to the ultra-thin size and excellent properties. Modulation of the properties of 2D materials through doping and interlayer van der Waals interactions has been one of the hot research topics. Recently, new 2D boron-carbon-nitrogen structures through doping graphene with boron-nitrogen, such as C3N and C3B, have been found to exhibit very rich physical properties. However, the structures of other 2D B-C-N materials and their properties are still unclear. To address this scientific problem, this project will theoretically design 2D B-C-N crystal structures with different configurations so that the intrinsic band gaps exhibited by these systems could be continuously tuned in a wide range, and investigate the novel physical properties of their Moiré structures under different stacking conditions. This project will not only use the first-principles density functional theory to simulate the electronic structure and optical properties, but also use our recently developed fast GW calculation method to investigate the quasiparticle properties and excitonic effects of the new 2D B-C-N structures. Through the implementation of this project, it is expected to accurately predict the electronic and optical properties of 2D B-C-N, and to master the methods of tuning its properties, and to provide theoretical support for the experimental synthesis and performance design, thus this project is of great practical significance.