Strong second harmonic generation (SHG) in monolayer transition metal dichalcogenides demonstrates great promise for nonlinear photonic applications. However, to utilize these materials in photonic applications, it is imperative to investigate the robustness of the nonlinear optical properties against various defects introduced during or post synthesis. Here we study the SHG in hexagonal monolayer WS 2 with synthesis defects, in triangular monolayer WS 2 with focused ion beam induced structural defects, and in WS 2 under ambient and aqueous environmental conditions. We find that WS 2 hexagonal monolayers exhibit significantly more uniform SHG intensity across the sample with a coefficient of variation, ##IMG## [http://ej.iop.org/images/2053-1583/7/4/045020/tdmaba564ieqn1.gif] {${c_v} = 4.9\% $} than the varying photoluminescence (PL) intensity ( ##IMG## [http://ej.iop.org/images...] {${c_v} = 32.83\% $}

中文翻译：

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具有生长和合成后缺陷的二维过渡金属二硫化氢二次谐波的产生

单层过渡金属二硫化二氢中的强二次谐波（SHG）表现出对非线性光子应用的巨大希望。然而，为了在光子应用中利用这些材料，必须研究非线性光学特性对合成期间或合成后引入的各种缺陷的鲁棒性。在这里，我们研究在具有合成缺陷的六边形单层WS 2，在聚焦离子束引起的结构缺陷的三角形单层WS 2中以及在环境和水环境条件下的WS 2中的SHG。我们发现WS 2六角形单分子层在样品上表现出明显更均匀的SHG强度，并具有变异系数## IMG ## [http://ej.iop.org/images/2053-1583/7/4/045020/ tdmaba564ieqn1.gif] {$ {c_v} = 4。