Özeren Mehmet Derya, Pekker Áron, Kamarás Katalin, Botka Bea
Institute for Solid State Physics and Optics, Wigner Research Centre for Physics Konkoly Thege u. 29-33 H-1121 Budapest Hungary
Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics Műegyetem rkp. 3 H-1111 Budapest Hungary.
RSC Adv. 2022 Oct 11;12(44):28853-28861. doi: 10.1039/d2ra04278a. eCollection 2022 Oct 4.
Surface passivation is one of the commonly used approaches to reduce the density of defects on the surfaces and interfaces hindering the performance and stability of perovskite optoelectronic devices. Although surface passivation leads to performance improvement for the targeted devices, details of the complex intermolecular interactions occurring between the molecules and perovskites are not entirely known. Here, we investigated a variety of commonly used solvents in the post-processing of perovskites by using photoluminescence (PL) spectroscopy on single and mixed halide perovskites (MAPbI, MAPbBr and MAPb(BrI)). Our results show that solvents with medium and low Gutmann donor and acceptor numbers provide PL intensity increase for both single halide perovskites by passivating the surface defect sites. Among the single halide perovskites, MAPbBr is more attracted to hydrogen bonding solvents, in contrast to MAPbI that is preferred by Lewis bases. This halide selective attraction also has an influence on the mixed-halide composition. Identifying these interaction mechanisms provides new insights into passivating the surface of perovskites for future device design.
表面钝化是常用的降低表面和界面缺陷密度的方法之一，这些缺陷会阻碍钙钛矿光电器件的性能和稳定性。尽管表面钝化能提高目标器件的性能，但分子与钙钛矿之间发生的复杂分子间相互作用的细节尚不完全清楚。在此，我们通过对单卤化物和混合卤化物钙钛矿（MAPbI、MAPbBr和MAPb(BrI)）进行光致发光（PL）光谱研究，考察了钙钛矿后处理中常用的多种溶剂。我们的结果表明，具有中等和低古特曼给体和受体数的溶剂通过钝化表面缺陷位点，使单卤化物钙钛矿的PL强度增加。在单卤化物钙钛矿中，MAPbBr更容易被氢键溶剂吸引，而MAPbI则更受路易斯碱的青睐。这种卤化物选择性吸引也会影响混合卤化物的组成。识别这些相互作用机制为未来器件设计中钝化钙钛矿表面提供了新的见解。
