新型二维铁电材料及其应用的理论设计

Ferroelectric materials, owing to their intrinsic tunable electric polarization with an external electric field, have great potentials in a variety of applications such as microelectronic devices. However, among the over one hundred van der Waals two-dimensional materials represented by graphene discovered in recent years, none of them is ferroelectric with out-of-plane electric polarization. This proposal, based on our newly discovered two-dimensional ferroelectric material, In2Se3, aims to (1) search for other similar two-dimensional ferroelectric materials with out-of-plane electric polarization; (2) explore potential applications of such two-dimensional ferroelectric materials in multilayer van der Waals heterostructures; and (3) design two-dimensional multiferroic materials based on the two-dimensional ferroelectric materials via magnetic doping, using first-principles calculation within the framework of density functional theory. We believe that the success of this research will further expand the family of two-dimensional materials with new functionalities and offer new opportunities for their practical applications.

铁电材料，由于其自身存在可通过外电场操纵的电极化，在微电子器件等诸多领域具有巨大的应用前景。然而，在近年来蓬勃发展起来的百余种以石墨烯为代表的范德华二维材料中， 还没有一个稳定的二维材料具有垂直于二维面方向极化的铁电性。本项目以本研究组最近发现的世界上首个稳定的具有垂直于二维面方向极化的铁电材料In2Se3为基础，利用基于密度泛函理论的第一性原理计算：（1）搜寻与之类似的其它具有垂直于二维面方向极化的铁电材料；（2）探索此类二维铁电材料在多层范德华异质结构中可能的应用；（3）通过磁性掺杂设计二维多铁材料。我们相信本项目的成功实施将进一步拓展二维材料家族并为其增添新的功能性，为二维材料的应用开辟新的领域和机遇。

该项目的主要围绕新型二维铁电材料及其应用的理论设计，主要研究成果包括：理论预言了以In2Se3为代表的首类同时具有面内和面外方向极化且相互耦合的稳定单层室温范德华二维铁电材料；基于该二维铁电材料，理论设计了利用其作为衬底实现外电场有效调控所放置在其表面的酞菁分子的磁性的新型单分子功能器件；与实验合作实现了基于该二维铁电材料的二维铁电二极管、铁电三极管、以及新型平面场效应器件的演示；揭示了单层二维锑烯长动力学及其相变微观机理等。在该项目的资助下发表了包括Nature Communications、Science Bulletin、Advanced Materials、Advanced Functional Materials、Journal of the American Chemical Society、Nano Letters、ACS Nano等在内的SCI论文16篇。