新型二维层状材料性能调控及其界面特性的理论研究

The appearance of the two-dimensional materials with atomic layer has greatly broadened our understanding to the field of materials. Because of their tuneable electronic properties, 2DLM shows great prospect in functional design and nano-device applications. Currently, many of the unique characteristic of layered materials have been excavated, still more novel features are called for exploring. The detailed computer simulation on the structure and properties of 2DLM will undoubtedly provide a theoretical basis and guidance for experiment. By means of first-principles method, we are planning to focus on several new 2D layered materials with widespread concern, to systematically investigate their geometries, electronic structures and optical spectra, to explore how the defects, including saturation, functional group, composite and substrate etc., affect their characteristics, with the aim of finding a way to enhance certain performance of layered material via theoretical design. Based on our detailed studies on the atomic level, we will concentrate on tunning their behaviors on one hand and designing new nano-structures on the other hand. These studies could provide valuable theoretical results to the new materials design, and, to some sense, offer prediction or guide the corresponding experimental studies, which could in turn benefit materials design and the application studies.

单个原子层厚度的二维材料(2DLM)的出现极大地拓宽了人类对材料领域的认识。因其电子性质的可调控性,2DLM在纳米器件的功能设计和应用方面颇具前景。目前,层状材料的许多独特性质被相继发现,仍有更多新颖的性能值得去研究与探索。通过计算机模拟对2DLM的结构和性质进行更为深入、细致的研究无疑可为实验提供理论依据与设计指导。本项目拟以几种引起广泛关注的新型二维层状材料为立足点,以探索性能调控的有效途径、设计新纳米结构为创新,通过缺陷、掺杂、边界饱和、官能团修饰、吸附原子/分子、结构复合、衬底等方面来取长补短, 改善材料的性能,探讨调控作用的内在机理,设计具有预期电子和光学特征的新材料,为实验上实现纳米器件的功能设计和应用提供依据。

在该项目中,我们完成了一系列新型二维层状材料如磷烯，氮化硼，硅烯，C-N基材料，MoO2以及异质结的计算模拟研究，发表了17篇SCI收录的论文。具体地，我们发现过渡金属原子（如Fe，Mn，Ni，Co）吸附是一种可行的官能化磷烯纳米带的方法；氢化的双层氮化硼利用自身具有的内建电场的特点有效地降低了光生电子、空穴的复合几率，且体系满足水裂解制氢的必要条件，从计算所得的光学性质可以明显看出该构型能充分地利用可见光; 而且，还可以施加额外电场的方式去调控 H-BNBN-H 结构的带隙。H与F原子各自以50%的浓度下对硅烯表面进行修饰，体系较好地符合光解水制氢过程中对催化剂的要求。B或P掺杂的多孔石墨烯结构C2N将是可用于可见光水分解的潜力型光催化剂，而且C2N具有很好的电催化HER的潜力，并为优化替代Pt的HER活性开辟了一个新的窗口；锂饰g-CN应该是室温下很有前途的储氢材料；可用于氦分离的纳米多孔CN膜；嵌入Pd/Pt的CN单层作为CO氧化的有效催化剂；石墨烯的同素异形体Net W是一种高效的锂离子电池电极材料；MoO2是一种理想的具有高电容率和高迁移率的新型阳极材料；异质结构由于其优异的性能引起了很大的关注，如改变磷烯和氮化硼层之间的距离可以调节异质结的带隙。异质结SiC(GeC)/MoS2，C3N4/ß-As和C3N4/ß-Sb具有优异的电子和光学特性。