Mahmud Md Arafat, Duong The, Yin Yanting, Peng Jun, Wu Yiliang, Lu Teng, Pham Huyen T, Shen Heping, Walter Daniel, Nguyen Hieu T, Mozaffari Naeimeh, Tabi Grace Dansoa, Liu Yun, Andersson Gunther, Catchpole Kylie R, Weber Klaus J, White Thomas P
Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT, 2601, Australia.
Flinders Institute for Nanoscale Science and Technology, Flinders University, Adelaide, SA, 5042, Australia.
Small. 2020 Dec;16(49):e2005022. doi: 10.1002/smll.202005022. Epub 2020 Nov 17.
Dimensional engineering of perovskite solar cells has attracted significant research attention recently because of the potential to improve both device performance and stability. Here, a novel 2D passivation scheme for 3D perovskite solar cells is demonstrated using a mixed cation composition of 2D perovskite based on two different isomers of butylammonium iodide. The dual-cation 2D perovskite outperforms its single cation 2D counterparts in surface passivation quality, resulting in devices with an impressive open-circuit voltage of 1.21 V for a perovskite composition with an optical bandgap of ≈1.6 eV, and a champion efficiency of 23.27%. Using a combination of surface elemental analysis and valence electron spectra decomposition, it is shown that an in situ interaction between the 2D perovskite precursor and the 3D active layer results in surface intermixing of 3D and 2D perovskite phases, providing an effective combination of defect passivation and enhanced charge transfer, despite the semi-insulating nature of the 2D perovskite phase. The demonstration of the synergistic interaction of multiple organic spacer cations in a 2D passivation layer offers new opportunities for further enhancement of device performance with mixed dimensional perovskite solar cells.
近年来，钙钛矿太阳能电池的维度工程因其在提高器件性能和稳定性方面的潜力而备受研究关注。在此，基于碘化丁铵的两种不同异构体的混合阳离子组成的二维钙钛矿，展示了一种用于三维钙钛矿太阳能电池的新型二维钝化方案。这种双阳离子二维钙钛矿在表面钝化质量方面优于其单阳离子二维同类物，对于光学带隙约为1.6电子伏特的钙钛矿组成，所制备的器件开路电压高达1.21伏特，冠军效率达到23.27%。通过结合表面元素分析和价电子光谱分解表明，二维钙钛矿前驱体与三维活性层之间的原位相互作用导致三维和二维钙钛矿相的表面混合，尽管二维钙钛矿相具有半绝缘性质，但仍能实现缺陷钝化和电荷转移增强的有效结合。二维钝化层中多种有机间隔阳离子协同相互作用的证明为进一步提高混合维度钙钛矿太阳能电池的器件性能提供了新的机会。
