发表机构
Friedrich-Schiller-Universität Jena（耶拿弗里德里希·席勒大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过DFT和连续介质模型研究褶皱Janus MoSSe/MoSeS单层，发现面外极化随投影纵横比线性变化，并建立无需高阶参数的几何模型，为柔性纳米电子学提供设计规则。
AI 中文摘要
通过面外褶皱进行的应变梯度工程为调控二维（2D）材料的电子和机电性能提供了一条强有力的途径。在此，我们利用密度泛函理论（DFT）计算并结合连续介质弹性体模型，系统研究了褶皱Janus MoSSe/MoSeS单层的电子和挠曲电响应。通过探索不同的褶皱尺寸和压缩应变水平（5%-20%），我们表明当以纳米褶皱的投影纵横比为参数时，全局面外极化遵循线性行为。在此基础上，我们开发了一个包含有效二维挠曲电系数的物理基础几何模型，该模型无需高阶非线性参数即可准确预测DFT极化。原子和轨道分辨的电荷密度分析揭示了这一行为的微观起源：虽然中心Mo 4d轨道流形作为稳健的线性挠曲电核心，但局部曲率驱动了S 3p和Se 4p子层流形之间连续且化学不对称的电荷转移。我们的发现为利用基于Janus的挠曲电性用于柔性纳米电子学和光电子学建立了清晰的几何设计规则。
英文摘要
Strain-gradient engineering via out-of-plane wrinkling offers a powerful route to tune electronic and electromechanical properties in two-dimensional (2D) materials. Here, we systematically investigate the electronic and flexoelectric response of wrinkled Janus MoSSe/MoSeS monolayers using density functional theory (DFT) calculations coupled with continuum elastica modeling. Exploring varying wrinkle sizes and compressive strain levels ($5\%-20\%$), we show that the global out-of-plane polarization follows a linear behavior when parameterized by the projected aspect ratio of the nanowrinkles. On this basis, we develop a physically grounded geometric model incorporating an effective 2D flexoelectric coefficient, which accurately predicts DFT polarizations without requiring higher-order nonlinear parameters. Atom- and orbital-resolved charge density analyses reveal the microscopic origin of this behavior: while the central Mo $4d$-orbital manifold acts as a robust, linear flexoelectric core, local curvature drives continuous, chemically asymmetric charge transfer between the S $3p$ and Se $4p$ sublayer manifolds. Our findings establish clear geometric design rules for harnessing Janus-based flexoelectricity for flexible nanoelectronics and optoelectronics.
