论文标题
通过铁电偏振开关的2D Van der Waals异质结构的调谐带对齐和光学性能
Tuning Band Alignment and Optical Properties of 2D van der Waals Heterostructure via Ferroelectric Polarization Switching
论文作者
论文摘要
有利的带对齐方式和出色的可见光响应对于光化学水分裂至关重要。在这项工作中，我们从理论上研究了如何利用铁电偏振及其在方向上的可逆性来调节带比对和光吸收特性。为此，通过将单层MOS2与铁电IN2SE3接口构建2D Van der Waals异质结构（HTSS）。我们发现极化方向的切换已大大改变了带的对准，从而促进了不同类型的反应。在IN2SE3/MOS2/IN2SE3异质结构中，一个极化方向支持氢进化反应，而另一个极化方向可以有利于氧气进化反应。这些可用于创建可调的光催化剂材料，在这些材料中，可以通过极化开关选择性地控制还原反应。带比对的调节归因于自发极化引起的反应电位的转移。此外，形成的II型Van der waals HTS还显着改善了电荷分离并增强了可见光和红外区域的光吸收。我们的结果在设计范德华HTS的设计中铺平了一种方式，用于使用铁电材料进行水分。
Favourable band alignment and excellent visible light response are vital for photochemical water splitting. In this work, we have theoretically investigated how ferroelectric polarization and its reversibility in direction can be utilized to modulate the band alignment and optical absorption properties. For this objective, 2D van der Waals heterostructures (HTSs) are constructed by interfacing monolayer MoS2 with ferroelectric In2Se3. We find the switch of polarization direction has dramatically changed the band alignment, thus facilitating different type of reactions. In In2Se3/MoS2/In2Se3 heterostructures, one polarization direction supports hydrogen evolution reaction and another polarization direction can favour oxygen evolution reaction. These can be used to create tuneable photocatalyst materials where water reduction reactions can be selectively controlled by polarization switching. The modulation of band alignment is attributed to the shift of reaction potential caused by spontaneous polarization. Additionally, the formed type-II van der Waals HTSs also significantly improve charge separation and enhance the optical absorption in the visible and infrared regions. Our results pave a way in the design of van der Waals HTSs for water splitting using ferroelectric materials.
