2024 AIChE Annual Meeting
(409a) Cleaning up Halide Perovskite Crystallization for Robust Phase Stability
Authors
Fenning, D. - Presenter, University of California San Diego
Palmer, J., University of California, San Diego
Marchezi, P., University of California San Diego
Iwamoto, S., University of California, San Diego
Han, C., University of California, San Diego
Dolan, C. J., University of California, San Diego
Vossler, H., University of California, San Diego
Hossain, M., University of California, San Diego
Dunfield, S., University of California, San Diego
The compositional and process flexibility of perovskite halides is fundamentally attractive and has led to outstanding optoelectronic figures of merit. On the other hand, the same flexibility also gives rise to challenges in phase stability and process scalability. Perovskite films and devices are remarkably sensitive to the presence not only of secondary phases but also extrinsic impurities, whether intentionally or unintentionally introduced. This work focuses on understanding impurity effects on ink and film stability to achieve improved synthetic control and narrow variation. By studying the reaction chemistry in perovskite precursor inks containing alkylammonium chlorides, we highlight connections between ongoing ink reactions and their effects on solid state black phase stability. Design for ink stability using alternate alkylammonium chlorides opens new avenues for perovskite fabrication with wider fabrication windows but also alters the crystallization pathway. Using multi-modal in situ X-ray scattering and luminescence measurement, we reveal a templating of black phase crystallization when using alternative alkylammonium chlorides that benefits ultimate film quality and phase stability under elevated light and heat conditions. Focused on scalable anti-solvent free processes, this work highlights impurity and crystallization chemistry that reduces process variability and improves phase stability under intrinsic photovoltaics operating conditions of light and heat.