Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK.
Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
Nat Commun. 2015 Jan 30;6:6142. doi: 10.1038/ncomms7142.
To date, there have been a plethora of reports on different means to fabricate organic-inorganic metal halide perovskite thin films; however, the inorganic starting materials have been limited to halide-based anions. Here we study the role of the anions in the perovskite solution and their influence upon perovskite crystal growth, film formation and device performance. We find that by using a non-halide lead source (lead acetate) instead of lead chloride or iodide, the perovskite crystal growth is much faster, which allows us to obtain ultrasmooth and almost pinhole-free perovskite films by a simple one-step solution coating with only a few minutes annealing. This synthesis leads to improved device performance in planar heterojunction architectures and answers a critical question as to the role of the anion and excess organic component during crystallization. Our work paves the way to tune the crystal growth kinetics by simple chemistry.
迄今为止，已经有大量关于制造有机-无机金属卤化物钙钛矿薄膜的不同方法的报道；然而，无机起始材料仅限于卤化物阴离子。在这里，我们研究了阴离子在钙钛矿溶液中的作用及其对钙钛矿晶体生长、薄膜形成和器件性能的影响。我们发现，通过使用非卤化物铅源（醋酸铅）代替氯化铅或碘化铅，钙钛矿晶体生长速度要快得多，这使得我们能够通过简单的一步溶液涂层，在几分钟的退火时间内获得超光滑且几乎无针孔的钙钛矿薄膜。这种合成方法提高了平面异质结结构器件的性能，并回答了在结晶过程中阴离子和过量有机成分的作用这一关键问题。我们的工作为通过简单的化学方法来调整晶体生长动力学铺平了道路。
