Termination dependence and electric field modification of band alignment in a CNT/CH3NH3PbI3 heterojunction.
Termination dependence and electric field modification of band alignment in a CNT/CH3NH3PbI3 heterojunction.
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DOI：
10.1039/d1cp00914a
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
Q. Tan;Qianjin Wang;C. Zhang;Kunpeng Gao;Yuanfangzhou Wang;Chengjie Qing;Yingkai Liu;Dapeng Yu-Dapen
中科院分区：
文献类型：
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作者：
Q. Tan;Qianjin Wang;C. Zhang;Kunpeng Gao;Yuanfangzhou Wang;Chengjie Qing;Yingkai Liu;Dapeng Yu-Dapen
碳纳米管(CNT)和钙钛矿型复合材料兼具碳纳米管和钙钛矿的优点，在光伏和光电子器件中具有广阔的应用前景，引起了人们的广泛关注。了解异质结的能带对齐对于进一步提高性能至关重要。在这里，我们用密度泛函理论方法系统地研究了半导体碳纳米管/CH3NH3PbI3异质结的界面电子结构和光吸收。结果表明，CNT/PbI2端接的CH3NH3PbI3(001)表面异质结为I型能带排列，而CNT/CH3NH3PbI3(001)端接的CH3NH3PbI3(001)表面异质结为II型能带排列，这表明CNT/CH3NH3PbI3异质结中存在不同的载流子转移过程以及对能带排列的终止依赖性。进一步的研究表明，外加电场可以改变碳纳米管/CH3NH3PbI3异质结的能带排列类型。我们的结果首次揭示了碳纳米管/CH3NH3PbI3异质结的界面电子结构，这可能为设计光电子器件提供一条新的途径。
Carbon nanotube (CNT) and perovskite composite materials possessing the combined advantages of CNTs and perovskites have drawn substantial attention due to their promising applications in photovoltaic and optoelectronic devices. Understanding the band alignment of heterojunctions is crucial for further performance improvement. Here, we systematically investigated the interfacial electronic structure and optical absorption of a semiconducting CNT/CH3NH3PbI3 heterojunction via density functional theory calculations. It was found that the CNT/PbI2-terminated CH3NH3PbI3 (001) surface heterojunction is a type-I band alignment, while the CNT/CH3NH3I-terminated CH3NH3PbI3 (001) surface heterojunction is a type-II band alignment, suggesting the different charge carrier transfer processes as well as termination dependence of band alignment in the CNT/CH3NH3PbI3 heterojunction. Further investigation indicated that applying electric fields can modify the band alignment type in the CNT/CH3NH3PbI3 heterojunction. Our results provide the first insight into the interfacial electronic structure of the CNT/CH3NH3PbI3 heterojunction, which may give a new route for designing optoelectronic devices.