Marchal Nadège, Mosconi Edoardo, García-Espejo Gonzalo, Almutairi Tahani M, Quarti Claudio, Beljonne David, De Angelis Filippo
Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta" (CNR-SCITEC), Via Elce di Sotto 8, 06123 Perugia, Italy.
Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc, 20, B-7000 Mons, Belgium.
J Phys Chem Lett. 2021 Mar 18;12(10):2528-2535. doi: 10.1021/acs.jpclett.0c03843. Epub 2021 Mar 8.
Low-dimensional metal halide perovskites are being intensively investigated because of their higher stability and chemical versatility in comparison to their 3D counterparts. Unfortunately, this comes at the expense of the electronic and charge transport properties, limited by the reduced perovskite dimensionality. Cation engineering can be envisaged as a solution to tune and possibly further improve the material's optoelectronic properties. In this work, we screen and design new electronically active A-site cations that can promote charge transport across the inorganic layers. We show that hybridization of the valence band electronic states of the perovskite inorganic sublattice and the highest occupied molecular orbitals of the A-site organic cations can be tuned to exhibit a variety of optoelectronic properties. A significant interplay of A-cation size, electronic structure, and steric constraints is revealed, suggesting intriguing means of further tuning the 2D perovskite electronic structure toward achieving stable and efficient solar cell devices.
与三维金属卤化物钙钛矿相比，低维金属卤化物钙钛矿因其更高的稳定性和化学多样性而受到广泛研究。不幸的是，这是以牺牲电子和电荷传输性能为代价的，这受到钙钛矿维度降低的限制。阳离子工程可以被设想为一种调节并可能进一步改善材料光电性能的解决方案。在这项工作中，我们筛选并设计了新的具有电子活性的A位阳离子，其能够促进电荷在无机层间的传输。我们表明，钙钛矿无机亚晶格的价带电子态与A位有机阳离子的最高占据分子轨道之间的杂化可以被调节，以展现出多种光电性能。研究揭示了A阳离子尺寸、电子结构和空间位阻之间的显著相互作用，这为进一步调节二维钙钛矿电子结构以实现稳定且高效的太阳能电池器件提供了有趣的方法。
