二维多铁材料GeS的制备及多场耦合效应研究

低维多铁材料在传感器、光电器件以及非易失性存储器等微型化器件中有着巨大的应用前景。二维多铁材料GeS具有强耦合的平面内自发铁电极化和自发铁弹性晶格应变，低畴壁能量和小迁移障碍，且在室温及更高温度下是热力学稳定的，可以通过弹性应变工程有效地调节。本项目主要运用化学气相沉积技术制备高质量的单层或少层GeS晶体，通过拉曼光谱，二次谐波，原子力显微镜，压电力显微镜，透射电镜等方式对样品进行表征，通过对原子结构进行分析来证明样品的相结构和铁电铁弹机理，结合微观和宏观铁电测量，利用搭建的多场耦合（电场、光场和机械应力场）测试系统进行测试，研究铁电、铁弹非易失性存储原型器件等内容，深入研究二维多铁材料GeS作为非易失性存储器的可行性与多场耦合效应物理机制。

Low-dimensional multiferroic materials have great application prospects in miniaturized devices such as sensors, photoelectronic devices and non-volatile memories. The two-dimensional multiferroic material GeS has strong coupling in-plane spontaneous ferroelectric polarization and spontaneous ferroelastic lattice strain, low domain wall energy and small migration barriers, and these are thermodynamically stable at room temperature and higher, and can be elastic strain engineering adjusts effectively. This project mainly uses chemical vapor deposition technology to prepare high-quality single-layer or few-layer GeS crystals. The samples are characterized by Raman spectroscopy, second harmonic generation, atomic force microscopy, piezoelectric force microscopy, and transmission electron microscopy. The atomic structure is analyzed to prove the phase structure of the sample and the ferroelectric ferroelastic mechanism. Combined with micro and macro ferroelectric measurements, use the established multi-field coupling (electric field, light field and mechanical stress field) system for testing. Research ferroelectricity, ferroelastic non-volatile memory prototype devices, etc., and further study the feasibility of two-dimensional multiferroic material GeS as a non-volatile memory and the physical mechanism of multi-field coupling effects.