基于二维材料的新型非线性光学体系：范德华异质结和复合凝胶玻璃

The development of nonlinear optical (NLO) materials is important for technical innovation in photoelectronic industry, such as photoelectric conversion, photonic switch and computer. Owing to the contribution of quantum size effect, dielectric confinement effect, surface effect, and local field effect, low-dimensional especially two-dimensional (2D) materials, present much better NLO properties than bulk materials. But problems remain: (1) Single component material can hardly meet the full NLO requirement. (2) Liquid system is unstable and hard to be practically used. To solve these problems, we plan to carry out the following work: (1) Construct 2D Van der Waals Heterostructures and use them for NLO. The synergism of different 2D materials is expected to comprehensively improve the NLO properties of the whole system. (2) Embed 2D material in inorganic gel glasses with good transparency and physicochemical stability to prevent agglomeration and increase stability. The obtained materials are in solid state and can therefore be processed into differed shapes and used in devices. We investigate the technique for the construction of 2D Van der Waals Heterostructures and production of 2D material hybrid gel glasses. By using Z-scan and pumb-probe techniques, we further carry out systematical investigations in the NLO effects and ultrafast dynamics of the obtained materials. Our work will reveal the origination and strengthen mechanism of NLO effect in these new material systems and provide theoretical guidance for the development of new NLO materials.

非线性光学(NLO)材料的发展对推动光电转化、光开关、光计算机等光电子行业的技术进步意义重大。由于量子尺寸、介电限域、表面和局域场等效应的贡献，低维尤其是二维(2D)材料具有显著优于体材料的NLO性能，潜在应用价值重大。但尚存问题，主要体现在：(1)单一材料无法满足NLO的全面要求；(2)液相体系不稳定且无法实用化。针对此，本项目开展以下工作：(1)构筑2D材料范德华异质结，利用组元间的协同效应全面提升NLO性能；(2)将2D材料包埋于透明性好、理化性能稳定的无机凝胶玻璃基质，彻底杜绝其团聚、提高稳定性，并同步实现固相化以便加工成型，为最终器件化铺平道路。在此过程中，探索2D材料范德华异质结的构筑及复合凝胶玻璃的制备技术。借助Z扫描和泵浦-探测技术，系统表征和研究所获材料的NLO效应和超快动力学过程，揭示异质结和复合凝胶玻璃NLO效应的产生和强化机制，为研发高性能的新型NLO材料提供指导。

非线性光学(NLO)材料的发展对推动光电转化、光开关、光计算机等光电子行业的技术进步意义重大。由于量子尺寸、介电限域、表面和局域场等效应的贡献，低维尤其是二维(2D)材料具有显著优于体材料的NLO性能，潜在应用价值重大。但尚存问题，主要体现在：(1)单一材料无法满足NLO的全面要求；(2)液相体系不稳定且无法实用化。针对此，本项目开展了以下工作：(1)构筑了2D材料范德华异质结，利用组元间的协同效应实现了NLO性能的全面提升；(2)将2D材料包埋于透明性好、理化性能稳定的无机凝胶玻璃基质，彻底杜绝其团聚、提高稳定性，并同步实现固相化以便加工成型，为最终器件化铺平了道路。在此过程中，探索了2D材料范德华异质结的构筑及复合凝胶玻璃的制备技术。借助Z扫描和泵浦-探测技术，系统表征和研究了所获材料的NLO效应和超快动力学过程，揭示了异质结和复合凝胶玻璃NLO效应的产生和强化机制，为研发高性能的新型NLO材料提供指导。