Enhanced charge transport in 2D Perovskites via fluorination of organic cation
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Organic-inorganic halide perovskites incorporating two-dimensional (2D) structures have shown promise for enhancing the stability of perovskite solar cells (PSCs). However, the bulky spacer cations often limit charge transport. Here, we report on a simple approach based on molecular design of the organic spacer to improve the transport properties of 2D perovskites, and we use phenethylammonium (PEA) as an example. We demonstrate that by fluorine substitution on the para position in PEA to form 4-fluorophenethylammonium (F-PEA), the average phenyl ring centroid-centroid distances in the organic layer become shorter with better aligned stacking of perovskite sheets. The impact is enhanced orbital interactions and charge transport across adjacent inorganic layers as well as increased carrier lifetime and reduced trap density. Using a simple perovskite deposition at room temperature without using any additives, we obtained a power conversion efficiency of >13% for (F-PEA)2MA4Pb5I16-based PSCs. In addition, the thermal stability of 2D PSCs based on F-PEA is significantly enhanced compared to those based on PEA.
Date Issued
2019-04-10
Date Acceptance
2019-03-01
Citation
Journal of the American Chemical Society, 2019, 141 (14), pp.5972-5979
ISSN
1520-5126
Publisher
American Chemical Society
Start Page
5972
End Page
5979
Journal / Book Title
Journal of the American Chemical Society
Volume
141
Issue
14
Copyright Statement
© 2019 American Chemical Society
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/30882210
Subjects
03 Chemical Sciences
General Chemistry
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2019-03-18