%0 Journal Article
%A Xu, Zhenhua
%A Zeng, Linxiang
%A Hu, Jinlong
%A Wang, Zhenya
%A Zhang, Putao
%A Brabec, Christoph
%A Forberich, Karen
%A Mai, Yaohua
%A Guo, Fei
%T Reducing energy barrier of δ-to-α phase transition for printed formamidinium lead iodide photovoltaic devices
%J Nano energy
%V 91
%@ 2211-2855
%C Amsterdam [u.a.]
%I Elsevier
%M FZJ-2022-03321
%P 106658 -
%D 2022
%X Recent progress in perovskite photovoltaics has witnessed a growing interest in formamidinium lead iodide (FAPbI3), primarily due to its high efficiency potential and excellent stability. However, the high energy barrier of δ-to-α phase transition presents a major hurdle to fabricate phase-pure α-FAPbI3 layers. Here, we report a two-step phase transition process to deposit high-quality photovoltaic α-FAPbI3 films by printing method. This is realized by judicious selection of a Lewis base N-methyl-2-pyrrolidone (NMP) and its counter Lewis acid, which enables the regulation of intermediary phase to reduce the energy barrier. With fine tuning the phase transition pathway, phase-pure and stable α-FAPbI3 perovskite films are obtained, which yield solar devices with a champion efficiency of 21.35%. The printed mini-modules with active areas of 12.32 cm2 and 55.44 cm2 are also fabricated, giving efficiencies of 17.07% and 14.17%, respectively. This work provides new insights of α-FAPbI3 crystallization for constructing efficient and stable printed photovoltaic devices.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000717768500005
%R 10.1016/j.nanoen.2021.106658
%U https://juser.fz-juelich.de/record/909653