Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
Adv Mater. 2017 Oct;29(40). doi: 10.1002/adma.201701077. Epub 2017 Sep 11.
Perovskite solar cells (PSCs) based on cesium (Cs)- and rubidium (Rb)-containing perovskite films show highly reproducible performance; however, a fundamental understanding of these systems is still emerging. Herein, this study has systematically investigated the role of Cs and Rb cations in complete devices by examining the transport and recombination processes using current-voltage characteristics and impedance spectroscopy in the dark. As the credibility of these measurements depends on the performance of devices, this study has chosen two different PSCs, (MAFACs)Pb(IBr) (MA = CH NH , FA = CH(NH ) ) and (MAFACsRb)Pb(IBr) , yielding impressive performances of 19.5% and 21.1%, respectively. From detailed studies, this study surmises that the confluence of the low trap-assisted charge-carrier recombination, low resistance offered to holes at the perovskite/2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene interface with a low series resistance (R ), and low capacitance leads to the realization of higher performance when an extra Rb cation is incorporated into the absorber films. This study provides a thorough understanding of the impact of inorganic cations on the properties and performance of highly efficient devices, and also highlights new strategies to fabricate efficient multiple-cation-based PSCs.
钙钛矿太阳能电池（PSCs）基于含铯（Cs）和铷（Rb）的钙钛矿薄膜，表现出高度可重复的性能；然而，对这些系统的基本理解仍在不断发展。在此，本研究通过在暗态下使用电流-电压特性和阻抗谱研究了传输和复合过程，系统地研究了 Cs 和 Rb 阳离子在完整器件中的作用。由于这些测量的可信度取决于器件的性能，本研究选择了两种不同的 PSCs，（MAFACs）Pb（IBr）（MA = CH NH ，FA = CH（NH ） ）和（MAFACsRb）Pb（IBr），分别产生了 19.5%和 21.1%的令人印象深刻的性能。通过详细的研究，本研究推断，低陷阱辅助电荷载流子复合、在钙钛矿/2,2',7,7'-四（N,N-二对甲氧基苯基）-9,9-螺二芴界面处空穴的低电阻（R）和低电容的汇聚导致在吸收体薄膜中掺入额外的 Rb 阳离子时实现了更高的性能。本研究提供了对无机阳离子对高效器件性能和特性的影响的深入理解，并强调了制造高效多阳离子基 PSCs 的新策略。
