Engineering Commons^™

Reactions At Noble Metal Contacts With Methylammonium Lead Triiodide Perovskites: Role Of Underpotential Deposition And Electrochemistry, Ross A. Kerner, Philip Schulz, Jeffrey A. Christians, Sean P. Dunfield, Benjia Dou, Lianfeng Zhao, Glenn Teeter, Joseph J. Berry, Barry P. Rand

Faculty Publications

Chemical reactivity of halide perovskites coupled with a low energy of formation makes it a challenge to characterize material properties and achieve long-term device stability. In this study, we elucidate electrochemical reactions occurring at the methylammonium lead triiodide (MAPbI₃)/Au interface. X-ray photoemission spectroscopy is used to identify a type of reduction/oxidation reaction termed underpotential deposition (UPD) involving lead, iodine, and hydrogen occurring at interfaces with noble metals. Changes in surface compositions and oxidation states suggest that UPD derived adsorbates at MAPbI₃/Au interfaces lower the energy barrier for release of volatile HI and/or I₂catalyzing degradation …