Distinguishing electron diffusion and extraction in methylammonium lead iodide
Abstract
Charge diffusion and extraction are crucial steps in the operation of solar cells. Here we show that time-resolved photoluminescence can be used to study electron diffusion in hybrid perovskite films and subsequent transfer to the adjacent electron extraction layer. As diffusion and transfer to the extraction layer are consecutive processes, they can be hard to distinguish, but by exciting from each side of the sample we can separate them and identify which process limits charge extraction. We find that the introduction of a fullerene monolayer between the methylammonium lead iodide (MAPbI3) and the electron-transporting SnO2 layers greatly increases the electron transfer velocity between them to the extent that electron diffusion limits the rate of electron extraction. Our results suggest that increasing the electron diffusion coefficient in MAPbI3 would further enhance the electron extraction rate, which could result in more efficient n–i–p type solar cells.
Citation
Brown , P , Ruseckas , A , Krishnan Jagadamma , L , Blaszczyk , O , Harwell , J R , Mica , N A , Zysman-Colman , E & Samuel , I D W 2023 , ' Distinguishing electron diffusion and extraction in methylammonium lead iodide ' , The Journal of Physical Chemistry Letters , vol. 14 , pp. 3007–3013 . https://doi.org/10.1021/acs.jpclett.3c00082
Publication
The Journal of Physical Chemistry Letters
Status
Peer reviewed
ISSN
1948-7185Type
Journal article
Rights
Copyright © 2023 The Authors. Published by American Chemical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder.
Description
We are grateful to EPSRC for equipment and research grants (EP/L017008/1 and EP/R035164/1) and for a Ph.D. studentship to P.E.B. (EP/R513337/1). Dr. L. K. Jagadamma acknowledges support from a Marie Skłodowska-Curie Individual Fellowship (745776) and funding from UKRI-FLF through grant MR/T022094/1.Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.