Electronic structures and photovoltaic applications of vdW heterostructures based on Janus group-IV monochalcogenides: insights from first-principles calculations
Electronic structures and photovoltaic applications of vdW heterostructures based on Janus group-IV monochalcogenides: insights from first-principles calculations
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DOI：
10.1039/d2cp05663a
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发表时间：
2023-01-20
影响因子：
3.3
通讯作者：
Su, Yan
中科院分区：
文献类型：
--
作者：
Cheng, Kai;Hu, Wenbo;Su, Yan
货车德瓦尔斯积分可以帮助二维材料调节其性能，并为二维材料在下一代高性能光电器件中提供更多的机会。利用第一性原理计算，我们探索了二维原始和Janus第四族单硫族化合物的原子和电子结构，并发现在Janus第四族单硫族化合物的内部垂直电场。然后，我们构建了vdW异质结与原始和Janus组-IV单硫属化合物单层作为积木，并探讨了它们的原子结构和能带排列。我们的研究结果表明，这些vdW异质结构可以在实验上合成，并在界面处的Janus单层的表面终止可以显着地帮助异质结构实现从I型到II型的转变，由于本征电场。此外，我们发现了8个vdW异质结与小于5%的失配表现出II型能带对准的VBM和CBM的电荷密度主要集中在不同的异质结域，和优良的功率转换效率（类似于19%）在photochemics也预测这些异质结与II型能带对准。我们的研究结果不仅给出了一个想法，使用Janus单层作为构建块来构建vdW异质结构和调制它们的能带排列，但也提供了一个指导实验研究人员设计更有效的光伏器件与Janus第IV族单硫族化合物。
The van der Waals integration can help 2D materials modulate their properties and provide more opportunities for 2D materials in the next-generation high-performance optoelectronic devices. Using first-principles calculations, we explored the atomic and electronic structures of 2D pristine and Janus group-IV monochalcogenides and found the internal vertical electric field at Janus group-IV monochalcogenides. Then, we constructed vdW heterostructures with pristine and Janus group-IV monochalcogenides monolayers as building blocks and explored their atomic structures and band alignments. Our results demonstrate that these vdW heterostructures can be synthesized experimentally, and the surface termination of the Janus monolayer at the interface can significantly help the heterostructure realize the transition from type I to type II due to the intrinsic electric field. Moreover, we found eight vdW heterostructures with a mismatch of less than 5% exhibiting type II band alignment with charge densities of VBM and CBM mainly localized at different domains of heterostructures, and excellent power conversion efficiency (similar to 19%) in photovoltaics are also predicted for these heterostructures with type II band alignment. Our results not only give an idea to use the Janus monolayer as building blocks to construct vdW heterostructures and modulate their band alignment but also provide a guide to the experimental researcher to design more efficient photovoltaic devices with Janus group-IV monochalcogenides.