Spatially Non-uniform Trap State Densities in Solution-Processed Hybrid Perovskite Thin Films

Sergiu Draguta, Siddharatha Thakur, Yurii V. Morozov, Yuanxing Wang, Joseph S. Manser, Prashant V. Kamat, Masaru Kuno

Research output: Contribution to journalArticlepeer-review

160 Scopus citations


The facile solution-processability of methylammonium lead halide (CH3NH3PbI3) perovskites has catalyzed the development of inexpensive, hybrid perovskite-based optoelectronics. It is apparent, though, that solution-processed CH3NH3PbI3 films possess local emission heterogeneities, stemming from electronic disorder in the material. Herein we investigate the spatially resolved emission properties of CH3NH3PbI3 thin films through detailed emission intensity versus excitation intensity measurements. These studies enable us to establish the existence of nonuniform trap density variations wherein regions of CH3NH3PbI3 films exhibit effective free carrier recombination while others exhibit emission dynamics strongly influenced by the presence of trap states. Such trap density variations lead to spatially varying emission quantum yields and correspondingly impact the performance of both methylammonium lead halide perovskite solar cells and other hybrid perovskite-based devices. Of additional note is that the observed spatial extent of the optical disorder extends over length scales greater than that of underlying crystalline domains, suggesting the existence of other factors, beyond grain boundary-related nonradiative recombination channels, which lead to significant intrafilm optical heterogeneities.
Original languageEnglish (US)
Pages (from-to)715-721
Number of pages7
JournalJournal of Physical Chemistry Letters
Issue number4
StatePublished - Feb 3 2016
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2022-05-31
Acknowledged KAUST grant number(s): OCRF-2014-CRG3-2268
Acknowledgements: We thank the Office of Basic Energy Sciences of the U.S. Department of Energy through Grant DE-SC0014334 and the Center for Sustainable Energy at Notre Dame (ND Energy) for financial support of this study. We also thank the Notre Dame Radiation Laboratory for use of its facilities (NDRL 5103). J.S.M. acknowledges the support of King Abdullah University of Science and Technology (KAUST) through Award OCRF-2014-CRG3-2268. We thank the ND Energy Materials Characterization Facility (MCF) for the use of the Bruker D8 Advance Davinci powder X-ray diffractometer. The MCF is funded by the Sustainable Energy Initiative (SEI), which is part of the Center for Sustainable Energy at Notre Dame (ND Energy).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.

ASJC Scopus subject areas

  • General Materials Science


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