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arXiv 2104.03077cond-mat.mtrl-sci
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二维3R双层膜BX(X=P,As,Sb)的光电性和铁电性的普遍共存

Universal co-existence of photovoltaics and ferroelectricity from two-dimensional 3R bilayer BX (X=P, As, Sb)

Qiang Wang, Yan Liang, Hui Yao, Jianwei Li, Tianwei Liu, Bin Wang

摘要:

二维材料中铁电性和光伏性的相互交织将使光伏性能的改善和控制成为可能。本文以2D 3R双层BX(X=P,As,Sb)为模型体系,研究了本征2Dout-of-plane(OOP)铁电材料的光伏特性,并试图探索通过改变铁电极化强度来调控其光电性能的策略。由于特殊的3R堆积引起的空间反转对称性破缺,在3R双层BX中会出现自发的OOP铁电极化,这种极化可以通过特定的层间滑动进行切换。OOP铁电性导致层间电荷转移,实现空穴和电子的有效空间分离,形成II型能带排列特性。此外,由于两个相同层的完美晶格匹配,3R双层BX比大多数传统的由不同材料制成的2D异质结构更稳定,并且在实验中更容易实现。3R双层BX具有中等的带隙、超高的载流子迁移率和有效的光吸收,其纳米器件具有大的光电流、高的光子响应率和优异的外量子效率。更重要的是,所有这些光电参数取决于本征OOP铁电强度。通过改变双层BX的层间距,可以有效地调节铁电极化,以达到最佳的光电性能。最后,我们强调了空间反转对称性破缺在3R双层BX之外的层状材料中实现铁电和光致发光协同调控的重要性和普遍性。

英文摘要:

The intertwined ferroelectricity and photovoltaics in two-dimensional (2D) materials will enable the favorable improvement and control of photovoltaic preformances. In this paper, we take 2D 3R bilayer BX (X=P, As, Sb) as model systems to study the photovoltaic characteristics of intrinsic 2D out-of-plane (OOP) ferroelectric material, and try to explore a strategy to regulate the photoelectric properties by changing the strength of ferroelectric polarization. Due to the spatial inversion symmetry broken caused by special 3R stacking, spontaneous OOP ferroelectric polarization will appear in the 3R bilayer BX, which can be swichable through a specific interlayer sliding. The OOP ferroelectricity leads to charge transfer between layers, realizes efficient spatial separation between holes and electrons, and forms the characteristics of type-II band alignment. Moreover, due to perfect lattice match on account of two identical layers, the 3R bilayer BX is more stable and easy to realize in experiments than most of traditional 2D heterostructures made up of different materials. The 3R bilayer BX shows moderate band gap, ultra-high carrier mobility and efficient optical absorption, and its nano-devices present large photocurrent, high photon responsivity and excellent external quantum efficiency. More importantly, all these photoelectric parameters depend on the intrinsic OOP ferroelectric strength. By changing the interlayer distance of bilayer BX, the ferroelectric polarization can be regulated effectively to achieve the optimal photoelectric performance. Finally, we emphasize the importance and universality of spatial inversion symmetry broken in layered materials beyond the 3R bilayer BX to realize the co-regulation of ferroelectric and photovoltaics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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