Hot-Hole cooling controls the initial ultrafast relaxation in methylammonium lead iodide perovskite
MetadataShow full item record
Understanding the initial ultrafast excited state dynamics of methylammonium lead iodide (MAPI) perovskite is of vital importance to enable its fullest utilisation in optoelectronic devices and the design of improved materials. Here we have combined advanced measurements of the ultrafast photoluminescence from MAPI films up to 0.6 eV above the relaxed excited state with cutting-edge advanced non-adiabatic quantum dynamics simulations, to provide a powerful unique insight into the earliest time behaviour in MAPI. Our joint experimental-theoretical approach highlights that the cooling of holes from deep in the valence band to the valence band edge is fast, occurring on a 100-500 fs timescale. Cooling of electrons from high in the conduction band to the conduction band edge, however, is much slower, on the order of 1-10 ps. Density of states calculations indicate that excited states with holes deep in the valence band are greatly favoured upon photoexcitation, and this matches well with the fast (100-500 fs) formation time for the relaxed excited state observed in our ultrafast PL measurements. Consequently we are able to provide a complete observation of the initial excited state evolution in this important prototypical material.
Hedley , G J , Quarti , C , Harwell , J R , Prezhdo , O , Beljonne , D & Samuel , I D W 2018 , ' Hot-Hole cooling controls the initial ultrafast relaxation in methylammonium lead iodide perovskite ' , Scientific Reports , vol. 8 , 8115 . https://doi.org/10.1038/s41598-018-26207-9
© 2018, the Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
DescriptionFunding: EPSRC (grants EP/J009016 and EP/L017008) and the European Research Council (grant 321305). IDWS acknowledges a Royal Society Wolfson Research Merit Award.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.