Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Department of Chemistry, National Central University , Chung-Li 32001, Taiwan.
J Am Chem Soc. 2018 Jan 10;140(1):388-393. doi: 10.1021/jacs.7b10898. Epub 2017 Dec 21.
Developing dopant-free hole transporting layers (HTLs) is critical in achieving high-performance and robust state-of-the-art perovskite photovoltaics, especially for the air-sensitive tin-based perovskite systems. The commonly used HTLs require hygroscopic dopants and additives for optimal performance, which adds extra cost to manufacturing and limits long-term device stability. Here we demonstrate the use of a novel tetrakis-triphenylamine (TPE) small molecule prepared by a facile synthetic route as a superior dopant-free HTL for lead-free tin-based perovskite solar cells. The best-performing tin iodide perovskite cells employing the novel mixed-cation ethylenediammonium/formamidinium with the dopant-free TPE HTL achieve a power conversion efficiency as high as 7.23%, ascribed to the HTL's suitable band alignment and excellent hole extraction/collection properties. This efficiency is one of the highest reported so far for tin halide perovskite systems, highlighting potential application of TPE HTL material in low-cost high-performance tin-based perovskite solar cells.
开发无掺杂空穴传输层（HTL）对于实现高性能和稳健的先进钙钛矿光伏至关重要，特别是对于对空气敏感的锡基钙钛矿体系。常用的 HTL 需要吸湿性掺杂剂和添加剂才能达到最佳性能，这增加了制造成本，并限制了长期设备稳定性。在这里，我们展示了一种新型的四（三苯基胺）（TPE）小分子的应用，该小分子通过简便的合成路线制备，可用作无掺杂的 HTL，用于制备无铅锡基钙钛矿太阳能电池。采用新型混合阳离子乙二胺/甲脒和无掺杂 TPE HTL 的性能最佳的碘化锡钙钛矿电池实现了高达 7.23%的功率转换效率，这归因于 HTL 合适的能带排列和优异的空穴提取/收集性能。该效率是迄今为止报道的锡卤化物钙钛矿体系中最高的之一，突出了 TPE HTL 材料在低成本高性能锡基钙钛矿太阳能电池中的潜在应用。
