Peng Yi, Fang Li, Lv Hui, Wang Guangzhao
School of Science, Hubei University of Technology, Wuhan 430068, P. R. China.
Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, School of Electronic Information Engineering, Yangtze Normal University, Chongqing 408100, P. R. China.
Langmuir. 2024 Sep 17;40(37):19861-19869. doi: 10.1021/acs.langmuir.4c02818. Epub 2024 Sep 6.
In this study, a Janus BiTeCl/SnSe van der Waals (vdW) heterostructure is constructed and systematically investigated for its potential in solar cell applications using first-principles calculations. The heterostructure introduces distinct contact interfaces (Cl-Se and Te-Se), both exhibiting a type-II band alignment. However, the conduction band minimum (CBM) and valence band maximum (VBM) contributions vary, depending on the interface. The Cl-Se interface demonstrates a significantly higher power conversion efficiency (PCE) of 20.11%, attributed to the suitable bandgap of the SnSe donor material and a smaller conduction band offset. Both interfaces exhibit enhanced optical properties compared to those of isolated BiTeCl and SnSe monolayers. Additionally, the electronic structure of the heterostructure is tunable via biaxial strain and electric fields, enabling further optimization of the PCE. Moreover, optical absorption can be adjusted by biaxial strain and electric fields. These findings position the Janus BiTeCl/SnSe heterostructure, particularly the Cl-Se interface, as a promising candidate for next-generation photovoltaic devices, offering both high efficiency and an external tunability.
在本研究中，构建了一种Janus BiTeCl/SnSe范德华（vdW）异质结构，并使用第一性原理计算系统地研究了其在太阳能电池应用中的潜力。该异质结构引入了不同的接触界面（Cl-Se和Te-Se），两者均呈现II型能带排列。然而，导带最小值（CBM）和价带最大值（VBM）的贡献因界面而异。Cl-Se界面展现出20.11%的显著更高的功率转换效率（PCE），这归因于SnSe供体材料合适的带隙和较小的导带偏移。与孤立的BiTeCl和SnSe单层相比，两个界面均表现出增强的光学性质。此外，异质结构的电子结构可通过双轴应变和电场进行调节，从而实现PCE的进一步优化。而且，光吸收可通过双轴应变和电场进行调整。这些发现使Janus BiTeCl/SnSe异质结构，特别是Cl-Se界面，成为下一代光伏器件的有前景的候选者，兼具高效率和外部可调性。
