热电材料作为环境友好型清洁能源转换材料，符合国家新能源发展重大战略。石墨烯(GE)和过渡金属硫族化物(MX2, M=Mo, W; X=S, Se, Te)是典型的二维(2D)层状材料，分别具有高电导率和热电势，在热电研究领域开始引起重大关注。MX2和GE均可实现溶液处理，易于制备异质结构复合薄膜，其层状结构有利于降低材料的费米能级和热导率，解决单一材料性能(电导率、热电势或热导率)短板所造成的缺陷，从而制备高性能薄膜热电材料。本项目旨在以MX2和GE为主体材料，采用直接剥离和化学气相沉淀等方法及悬涂、抽滤等技术制备新型2D层状异质结构的MX2/GE复合薄膜。通过优化结构和成分，探索其热电性能与结构、组成、温度、电子传输和热传导性能之间的关系。冀望于GE和MX2之间形成有效互补，改善电导率和热电势，降低热导率，提高热电性能，为构筑高性能2D层状无机非金属复合热电薄膜材料提供理论指导。

Thermoelectric materials, an environmentally friendly clean energy, meet the demand of China’s new energy development strategy with a prosperous application in thermoelectric power generation and refrigeration. Two-dimensional (2D) materials, such as graphene (GE) and transition metal dichalcogenides (MX2, M=Mo, W; X=S, Se, Te), have historically been one of the most extensively studied classes of materials due to the wealth of unusual physicochemical properties. GE and MX2 have high electrical conductivity and thermopower, respectively, and both can be processed in aqueous solution. Owing to their layered nature, atoms are strongly bonded within the same plane but only weakly attached to sheets above and below by van der Waals forces. This weak interlayer interaction makes the extraction of sin¬gle or a few layers of atoms possible, thus leading to the burgeoning research on the thermoelectric property of 2D heterostructures and layered thin films obtained using liquid exfoliation and chemical vapor deposition (CVD) methods. Additionally, the heterostructures of MX2/GE can efficiently decrease the Femi level and thermal conductivity of composite thin-film leading to a better thermoelectric performance. The main objective of this project to construct a singal layered (sl-), a few layered (fl-), or multilayered (ml-) MX2/GE composite thermoelectric thin-film material by spin-coating, filtration, layer-by-layer assembled techniques. The project design desires to adhere to the high conductivity, high carrier mobility and excellent environmental stability of graphene and the unique electronic structure and the high thermopower in order to achieve an effective complementary and enhancement for the 2D layered thermoelectric performance of composite thin-films with a low thermal conductivity. A series of work need to be done such as optimizing the prepared conditions of MX2/GE composite and adjusting the compositions and structures. Additionally, special attentions will be paid to the study on the relation between thermoelectric property and temperature and electron transport, and the ways to improve the thermoelectric property of MX2/GE thin-film, as well as to develop a new method for high performance composite thin-film thermoelectric materials. Accomplishment of this project will provide valuable theoretic foundation and experimental support for the development of novel composite thin-film thermoelectric materials.