Presentation Details
| How Moisture and Oxygen Influence Antisolvent-Free Perovskite Crystallization Pathways Maimur Hossain1, Connor J.Dolan1, Eric Oberholtz1, Darya Kamiyama1, Jack R.Palmer1, Paulo E.Marchezi1, Tim Kodalle2, Carolin Sutter-Fella 2, David P.Fenning1. 1University of California San Diego, San Diego, CA, USA.2Lawrence Berkeley National Laboratory, Berkeley, CA, USA |
Abstract
Gaining control over crystallization of metal halide perovskite (MHP) under ambient conditions would be beneficial for achieving reliable and scalable production of halide perovskite solar cells. Antisolvent-free deposition offers excellent compatibility with industrial-scale manufacturing but introduces fundamentally different crystallization dynamics compared to antisolvent methods, arising from altered interactions during processing. Through in situ wide-angle X-ray scattering, we elucidate the synergistic roles of oxygen and relative humidity (RH) in directing polytype evolution during ambient synthesis of perovskite films. In an N₂ (inert) atmosphere, crystallization proceeds via the relatively direct polytype transformation 2H→3C. Contrarily, crystallization in dry air (RH 0%) is dominated by oxygen-stabilized 4H intermediates, resulting in an alternative 2H → 4H→3C pathway. Introduction of moisture (RH 10%) minimizes the presence of 4H intermediates, reduces the temperature required for 3C phase emergence, and closely mirrors inert crystallization behavior 2H→3C. Solar cells fabricated under RH 10% conditions exhibited superior efficiency and operational stability compared to inert ones. Higher humidity (RH 40%) disrupted the balance and allowed the dominance of higher-order polytypes 4H/6H. These findings highlight controlled humidity as a critical parameter for enabling scalable ambient perovskite manufacturing.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.