Gong Jue, Adnani Moein, Jones Brendon T, Xin Yan, Wang Sisi, Patel Sawankumar V, Lochner Eric, Mattoussi Hedi, Hu Yan-Yan, Gao Hanwei
Department of Physics, Florida State University, Tallahassee, Florida 32306, United States.
Condensed Matter Science, National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States.
J Phys Chem Lett. 2022 May 12;13(18):4082-4089. doi: 10.1021/acs.jpclett.2c00862. Epub 2022 May 2.
Organic-inorganic hybrid perovskites have shown tremendous potential for optoelectronic applications. Ion migration within the crystal and across heterointerfaces, however, imposed severe problems with material degradation and performance loss in devices. Encapsulating hybrid perovskite with a thin physical barrier can be essential for suppressing the undesirable interfacial reactions without inhibiting the desirable transport of charge carriers. Here, we demonstrated that nanoscale, pinhole-free AlO layer can be coated directly on the perovskite CHNHPbI using atomic layer deposition (ALD). The success can be attributed to a multitude of strategies including surface molecular modification and hybrid ALD processing combining the thermal and plasma-enhanced modes. The AlO films provided remarkable protection to the underlying perovskite films, surviving by hours in solvents without noticeable decays in either structural or optical properties. The results advanced the understanding of applying ALD directly on hybrid perovskite and provided new opportunities to implement stable and high-performance devices based on the perovskites.
有机-无机杂化钙钛矿在光电子应用中展现出了巨大潜力。然而，晶体内部以及异质界面间的离子迁移给器件中的材料降解和性能损失带来了严重问题。用一层薄的物理屏障包裹杂化钙钛矿对于抑制不良界面反应同时又不阻碍电荷载流子的理想传输至关重要。在此，我们证明了可以使用原子层沉积（ALD）直接在钙钛矿CH₃NH₃PbI₃上涂覆纳米级、无针孔的Al₂O₃层。这一成功可归因于多种策略，包括表面分子改性以及结合热模式和等离子体增强模式的混合ALD工艺。Al₂O₃薄膜为下层的钙钛矿薄膜提供了显著的保护，在溶剂中放置数小时后，其结构和光学性质均无明显衰减。这些结果增进了对直接将ALD应用于杂化钙钛矿的理解，并为基于钙钛矿实现稳定且高性能的器件提供了新机遇。
