过渡金属二硫属化物和氮化硼合金的第一性原理二次谐波产生：从单层和纳米管到黑云母和黑云母
First principles second harmonic generation of transition metal dichalcogenides and boron nitride alloys: from monolayers and nanotubes to Haeckelites and Schwarzites
摘要：
为了揭示新的二维系统的二次谐波产生（SHG），利用第一性原理方法计算了不同类型的层状合金的二阶极化率χ（2），这些层状合金包括过渡金属二硫属化物（TMD）合金的单层、TMD Haeckelite合金、TMD合金的纳米管、包括BxNyCz合金的六方氮化硼（h-BN）系统、BN和BNC 2纳米管，BxNxCy黑克石和BN黑碳石（多孔BN）。结果表明，在高光子能量下，钨基合金的χ（2）值高于钼基合金，而在低光子能量下，一种MoSSe占主导地位。在所有计算结构中，假设的TMD海克尔体NbSSe和Nb 0.5Ta 0.5S2显示出最高的χ（2）。锯齿形TMD合金纳米管的χ（2）值随直径的减小而增大，当直径较大时，χ（2）值接近单层纳米管。BNC合金表现出比h-BN单层更高的χ（2），并且与TMD合金相当，除了一种情况使其强度加倍之外。BN管显示随着直径减小，χ（2）增加，类似于TMD纳米管。BxNxCy海克石具有非常高的χ（2），并且可能揭示扩展缺陷在非线性光学性质中的作用。BN Schwarzite之一表现出比已知的3-D材料更高的χ（2）。
英文摘要：
In order to shed light on the second harmonic generation (SHG) of new 2-D systems, first principles methods are used to calculate the second order susceptibility χ(2) for different types of layered alloys such as monolayers of transition metal dichalcogenide (TMD) alloys, TMD Haeckelite alloys, nanotubes of TMD alloys, hexagonal boron nitride (h-BN) systems which include BxNyCz alloys, BN and BNC2 nanotubes, BxNxCy Haeckelites and BN Schwarzites (porous BN). It is found that the tungsten based alloys possess higher χ(2) than Mo based at high photon energies, but at low energies, one type of MoSSe dominates. The hypothetical TMD Haeckelites NbSSe and Nb0.5Ta0.5S2 reveal the highest χ(2) of all the calculated structures. Zigzag TMD alloy nanotubes show higher χ(2) as the diameter is reduced and approximate to the monolayer for big diameters. BNC alloys exhibit a higher χ(2) than the h-BN monolayer and are comparable to TMD alloys, except for one case which doubles its intensity. The BN tubes show an increase of χ(2) as the diameter decreases, similarly to the TMD nanotubes. BxNxCy Haeckelites possess a very high χ(2) and may shed light on the role of extended defects in nonlinear optical properties. One of the BN Schwarzites exhibits a higher χ(2) than already known 3-D materials.
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。
