Cage Molecules Stabilize Lead Halide Perovskite Thin Films
Name
20220315_manuscript_v21.pdf
Description
Accepted version
Size
10.41 MB
Format
Adobe PDF
Checksum (MD5)
7412c8e79f122d52445cc68f350e2849
Author(s)
Sun, Shijing
Liu, Ming
Thapa, Janak
Hartono, Noor Titan Putri
Zhao, Yicheng
He, Donglin
Wieghold, Sarah
Chua, Matthew
Wu, Yue
Bulović, Vladimir
Date Issued
October 26, 2022
Journal
Chemistry of Materials
Publisher
American Chemical Society
Citation
Chem. Mater. 2022, 34, 21, 9384–9391.
Version
Author's final manuscript
Abstract
The environmental stability of hybrid organic–inorganic perovskite (HOIP) materials needs to increase to enable their widespread adoption in thin-film solar and optoelectronic devices. Molecular additives have recently emerged as an effective strategy for regulating HOIP crystal growth and passivating defects. However, to date the choice of additives is largely limited to a dozen or so materials under the design philosophy that high crystallinity is a prerequisite for stable HOIP thin films. In this study, we incorporate porous organic cages (POCs) as functional additives into perovskite thin films for the first time and investigate the HOIP–POC interaction via a combined experimental and computational approach. POCs are significantly larger than the small-molecule additives explored for HOIP synthesis to date but much smaller than polymeric sealants. Partially amorphized composites of MAPbI3 (methylammonium lead iodide, HOIP) and RCC3 (an amine POC) form a network-like surface topography and lead to an increase in the optical bandgap from 1.60 to 1.63 eV. Further in situ optical imaging suggests that RCC3 can delay the MAPbI3 film degradation onset up to 50× under heat and humidity stresses, showing promise for improving reliability in HOIP-based solar-cell and light-emitting applications. Furthermore, there is evidence of molecular interactions between RCC3 and MAPbI3, as fingerprinted by the suppressed N–H stretching mode in MA+ from Fourier transform infrared (FTIR) spectra and density functional theory (DFT) simulations that suggest strong hydrogen bonding between MA+ and RCC3. Given the diversity of POCs and HOIPs, our work opens a new avenue to stabilize HOIPs via tailored molecular interactions with functional organic materials.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
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Creative Commons Attribution-Noncommercial-ShareAlike
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DOI of Published Version
https://doi.org/10.1021/acs.chemmater.2c01502
