二维MoS2/ReS2的合金及异质结构

Two-dimensional materials have drawn great attentions because of their ultrathin thickness and excellent performance as electronic and opt-electronic devices. Two-dimensional alloys and heterostructures are very interesting since the alloys can tune the properties of 2D materials effectively and the heterostructures are the basis of integration of 2D materials for their practical applications. However, till today, the 2D alloys and heterostructures are still limited to h-BN/graphene and MoS2/WS2/MoSe2/WSe2 systems. In contrast, ReS2 has different crystal structure with MoS2, which might bring some new possibilities to tune the properties of 2D materials. Here we propose to use chemical vapor deposition method to synthesize MoxRe1-xS2 alloys and MoS2/ReS2 heterostructures. We will use Re doping to realize the phase transition from 2H to 1T phase in MoS2 by hydrothermal or chemical vapor deposition method, leading to a stable T phase alloy. Furthermore, we will systemically study the relationships between doping concentration and the physical properties such as band gap, conductivity and catalyst performance. The atomic structure of the interface between T phase ReS2 and H phase MoS2 heterostructures will also be studied in detail and the junction behavior and photovoltaic effect of this hetrostructure will be tested. At last, First principle will be used to calculate the properties of the MoxRe1-xS2 alloys and MoS2/ReS2 heterostructures to confirm the experimental conclusions.

二维材料由于其超薄的结构和优异的性质受到了科研工作者的广泛关注。其中，二维材料的合金和异质结构尤为重要，因为合金体系能系统地调控优化二维材料的性质，而异质结构是实现二维材料的集成与应用的基础。但目前已发展的二维半导体材料的合金和异质结构仍非常局限，主要集中在Mo/W的硫化物及硒化物体系。而硫化铼与硫化钼具有不同的晶体结构，因此会带来相变、光电性质大幅度改变等特性。本项目拟利用化学气相沉积的方法制备二者的合金及异质结构；通过铼替换钼原子引起的对硫化钼晶格提供额外的电子，实现硫化钼由2H相到1T相的转变，阐明组分与带隙、电学性质之间的构效关系，实现电学器件、催化性质的最优化，获得稳定高效的T相合金的催化剂；合成二者的异质结构，详细研究H相和T相单层晶体界面的原子结构与性质，表征此异质结构的光电磁性质；进一步结合第一性原理计算解释此合金与异质结构体系的光电磁和催化性质。

发展了化学气相沉积的方法合成高质量的单层的MoxRe1-xS2合金，实现了合金组分的连续可调，并明晰了MoxRe1-xS2合金的微观组分与宏观性质之间的构效关系，发现了材料结构相变与组分之间的关系。合成了MoS2与ReS2的异质结构，明晰了不同相异质界面的原子结构，并实现了其互相掺杂引起的n型和P型半导体行为。发展了高效率的电化学催化产氢的催化剂，通过对组分的调节得到1T相的MoxRe1-xS2合金，解决目前MoS2催化剂稳定性与催化效率不能兼得的难题，并拓展实现了MoS2掺杂的普适性新方法，得到了高效的MoS2基催化剂。