Stanton Robert, Trivedi Dhara J
Department of Physics, Clarkson University, Potsdam, New York 13699, United States.
Nano Lett. 2023 Dec 27;23(24):11932-11939. doi: 10.1021/acs.nanolett.3c04054. Epub 2023 Dec 15.
Interfacing perovskites with two-dimensional materials such as metal-organic frameworks (MOFs) for improved stability and electron or hole extraction has emerged as a promising path forward for the generation of highly efficient and stable solar cells. In this work, we examine the structural properties and excitation dynamics of two MOF-perovskite systems: UMCM309-a@MAPbI and ZrL3@MAPbI. We find that precise band alignment and electronegativity of the MOF-linkers are necessary to facilitate the capture of excited charge carriers. Furthermore, we demonstrate that intraband relaxation of hot electrons to the MOF subsystem results in optically disallowed transitions across the band gap, suppressing radiative recombination. Furthermore, we elucidate the key mechanisms associated with improved structural stability afforded to the perovskites by the two-dimensional MOFs, highlighting the necessity of broad surface coverage and strong MOF-perovskite interaction.
将钙钛矿与二维材料（如金属有机框架（MOF））相结合以提高稳定性以及电子或空穴提取效率，已成为生成高效稳定太阳能电池的一条有前景的途径。在这项工作中，我们研究了两种MOF-钙钛矿体系UMCM309-a@MAPbI和ZrL3@MAPbI的结构特性和激发动力学。我们发现，MOF连接体精确的能带排列和电负性对于促进激发电荷载流子的捕获是必要的。此外，我们证明热电子向MOF子系统的带内弛豫会导致在带隙上出现光学禁戒跃迁，从而抑制辐射复合。此外，我们阐明了二维MOF赋予钙钛矿改善的结构稳定性的关键机制，强调了广泛的表面覆盖和强烈的MOF-钙钛矿相互作用的必要性。
