Photo-energy Conversion Efficiency of CH3NH3PbI3/C60 Heterojunction Perovskite Solar Cells from First-principles
Photo-energy Conversion Efficiency of CH3NH3PbI3/C60 Heterojunction Perovskite Solar Cells from First-principles
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从第一原理看CH3NH3PbI3/C60异质结钙钛矿太阳能电池的光能转换效率
DOI：
10.1039/d0ma00853b
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
and Kaoru Ohno
中科院分区：
文献类型：
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作者：
Khian-Hooi Chew;Riichi Kuwahara;and Kaoru Ohno
卤化物钙钛矿已成为下一代太阳能电池最有潜力的候选者。在这项工作中，我们进行了全面的第一性原理研究的光电转换效率（PCE）的CH 3 NH3 PbI 3/C60异质结。由于钙钛矿太阳能电池（PSC）通常暴露于影响钙钛矿中的光物理学和电荷分离的显著温度变化，因此CH 3 NH3 PbI 3（MAPbI 3）的四相和六相的有限板被构造成具有相对于钙钛矿表面的不同取向的甲基铵（MA）阳离子。一个C60分子，作为电子受体和传输材料，被引入到MAPbI 3表面上的各个位置。使用详细的平衡方法，通过检查位于MAPbI 3或C60中的Kohn-Sham能量和轨道来确定异质结的PCE。我们的研究表明，MAPbI 3/C60异质结的稳定性、激子解离效率和PCE与MAPbI 3表面的MA取向和C60位置密切相关.这归因于MAPbI 3的极性行为。使用四方相异质结，如果满足某些表面条件，则可以实现η = 19%的高PCE。MA阳离子表面偶极子产生的内建电场促进了电子-空穴对的解离和电子向富勒烯的转移。另一方面，具有高温立方MAPbI 3结构的异质结表现出η ≤ 10%的PCE，而与MAPbI 3表面上的MA取向和C60无关。
Halide perovskites have emerged as the most potential candidate for the next-generation solar cells. In this work, we conduct a comprehensive first-principles study on the photo-energy conversion efficiency (PCE) of the CH3NH3PbI3/C60 heterojunction. Since perovskite solar cells (PSCs) are generally exposed to substantial temperature variations that affect the photo-physics and charge separation in the perovskites, finite slabs of both the tetragonal- and cubic-phases of CH3NH3PbI3 (MAPbI3) are constructed with different orientations of the methylammonium (MA) cation with respect to the perovskite surface. A C60 molecule, acting as an electron acceptor and transport material, is introduced at various positions on the MAPbI3 surface. Using the detailed balance approach, the PCE of the heterojunction is determined by examining the Kohn–Sham energies and orbitals located either in MAPbI3 or in C60. Our study reveals that the stability, the exciton dissociation efficiency, and the PCE of the tetragonal MAPbI3/C60 heterojunctions strongly depend on the MA orientation and the C60 position on the MAPbI3 surface. This is attributed to the polar behavior of MAPbI3. Using the tetragonal-phase heterojunction, a high PCE of η ∼ 19% can be achieved, if certain surface conditions are met. Built-in electric field originating from the surface dipoles of the MA cation facilitates the dissociation of electron–hole pairs and the electron transfer to fullerene. On the other hand, the heterojunction with a high-temperature cubic MAPbI3 structure exhibits a PCE of η ∼ 10%, regardless of the MA orientation and C60 on the MAPbI3 surface.