新型全二维结构石墨烯/过渡金属硫化物纳米复合材料的可控制备及超快饱和吸收性能研究

Photonic devices are key to the development of the contemporary high information-technology world. The obtaining of materials with ultrafast nonlinear optical performances is the essential part of the realization of their practical application. Transition metal sulfides have graphene-analogous two-dimensional (2D) nanostructure and complementary optoelectronics performance with graphene. Thus, the combination of graphene with monolayer transition metal sulfides with direct bandgaps is expected to further enhance the nonlinear performance of graphene. For the development of novel saturable absorber, this project, based on our previous work on the design, preparation and characterization of graphene and graphene-semiconductor composites, aims to controllably synthesize the "2D + 2D" nanocomposites of graphene and transition metal sulfides (MoS2, WS2, etc.) realizing the combination of graphene and monolayer transition metal sulfides; systematically investigate the influences of sizes (including quantum size), number of layers and ratio of transition metal sulfides as well as mutual interactions between graphene and transition metal sulfides on the photonics performance of the resulted materials; further study the mechanism of the nonlinear response; and design novel all 2D combined graphene/transition metal suldide saturable absorbers with tunable absorption bands and ultrafast recovery time. The photonics studies of the novel 2D composites of graphene/transition metal sulfides, which will be carried out by this project, will afford a good foundation for exploring their application in areas of nano-photonic devices such as ultrashort pulse mode-locking, light switches.

光子器件是当代信息技术发展的核心之一，具有超快非线性光学响应材料的获得是其应用实现不可或缺的重要环节。过渡金属硫化物与石墨烯拥有类似的二维纳米结构和互补的光电子学性质，其与石墨烯复合有望进一步提高石墨烯的非线性光学性能。面向新型超快饱和吸收材料的开发，本项目充分结合近几年申请者在石墨烯及其复合材料的设计、合成和性能方面的研究成果和经验积累，拟开展石墨烯和过渡金属硫化物(MoS2、WS2等)全二维复合纳米结构体系的可控制备，实现单分子层金属硫化物和石墨烯的复合；系统研究过渡金属硫化物纳米片的尺寸、层数、配比，以及与石墨烯的相互作用等对材料光子学性能的影响，合成具有吸收带宽可调、饱和恢复时间极短的新型石墨烯基全二维复合饱和吸收材料。本项目开展的新型全二维复合石墨烯/过渡金属硫化物纳米材料光子学性质研究，将为探索其在新一代纳米光子器件如超短脉冲锁模器、光开关等领域的应用奠定良好基础。

光子器件是当代信息技术发展的核心之一，具有超快非线性光学响应材料的获得是其应用实现不可或缺的重要环节。新型二维纳米材料因其独特的电学和光学性能，以及易于集成的二维纳米结构使得该类材料有望在新一代纳米光子器件如光调制器件、光开关等领域具有潜在应用前景。本项目在前期工作基础上采用多种手段包括溶剂热法设计合成了一系列形貌和结构可控的过渡金属硫化物二维纳米薄膜及其复合材料，并研究了其在光调制器件领域的应用，取得一系列重要的研究成果。本项目的顺利实施为更好地发掘石墨烯及类石墨烯材料的光子学应用潜力，开拓其新应用领域具有良好的带动作用。重要结果如下： 1）采用真空抽滤再组沉积技术基于液相剥离悬浮液制备了一系列晶圆尺寸的过渡金属硫化物二维纳米薄膜，并研究了其超快饱和吸收特性，发展了相应的超快吸收型光子调制器件和技术。2）采用溶剂热技术设计合成了一系列晶圆尺寸的、形貌和结构可控的过渡金属硫化物MoS2二维纳米薄膜，并研究了其生长机制及膜的超快饱和吸收特性。.. 共发表SCI论文12篇，包含ACS Nano 2篇(IF=13.334)、Nanoscale 3篇(IF= 7.76)、Chemistry A European Journal 1篇(IF=5.83)等。其中，发表在ACS Nano [7, 9260 (2013)]论文被SCI基本科学指标ESI评为热点论文“Hot paper”和高引用论文“Highly cited paper”；发表在Nanoscale [7, 2978 (2015)]论文，被遴选为2015年度热点论文“Hot paper”；发表于Chemistry A European Journal [DOI: 10.1002/chem.201604395 (2016)]论文，作为封面论文出版。获国际会议邀请报告1次，国内会议口头报告2次。