Please use this identifier to cite or link to this item:
Title: Compositional and morphological changes in water-induced early-stage degradation in lead halide perovskites
Authors: Chen, Shi
Solanki, Ankur
Pan, Jisheng
Sum, Tze Chien
Keywords: Engineering::Materials::Functional materials
Issue Date: 2019
Source: Chen, S., Solanki, A., Pan, J., & Sum, T. C. (2019). Compositional and morphological changes in water-induced early-stage degradation in lead halide perovskites. Coatings, 9(9), 535-. doi:10.3390/coatings9090535
Project: Ministry of Education AcRF Tier 2 (MOE2016-T2-1-034)
Singapore National Research Foundation Investigatorship Programme (NRF-NRFI-2018-04)
University of Macau startup fund (SRG2018-00140-IAPME)
Journal: Coatings
Abstract: With tremendous improvements in lead halide perovskite-based optoelectronic devices ranging from photovoltaics to light-emitting diodes, the instability problem stands as the primary challenge in their development. Among all factors, water is considered as one of the major culprits to the degradation of halide perovskite materials. For example, CH3NH3PbI3 (MAPbI3) and CH(NH2)2PbI3 (FAPbI3) decompose into PbI2 in days under ambient conditions. However, the intermediate changes of this degradation process are still not fully understood, especially the changes in early stage. Here we perform an in-situ investigation of the early-stage MAPbI3 and FAPbI3 degradation under high water vapor pressure. By probing the surface and bulk of perovskite samples using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and XRD, our findings clearly show that PbI2 formation surprisingly initiates below the top surface or at grain boundaries, thus offering no protection as a water-blocking layer on surface or grain boundaries to slow down the degradation process. Meanwhile, significant morphological changes are observed in both samples after water vapor exposure. In comparison, the integrity of MAPbI3 film degrades much faster than the FAPbI3 film against water vapor. Pinholes and large voids are found in MAPbI3 film while only small number of pinholes can be found in FAPbI3 film. However, the FAPbI3 film suffers from its phase instability, showing a fast α-to-δ phase transition. Our results highlight the importance of the compositional and morphological changes in the early stage degradation in perovskite materials.
ISSN: 2079-6412
DOI: 10.3390/coatings9090535
Schools: School of Physical and Mathematical Sciences 
Rights: © 2019 The Author(s). Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SPMS Journal Articles

Files in This Item:
File Description SizeFormat 
Compositional and Morphological Changes in Water-Induced Early-Stage Degradation in Lead Halide Perovskites.pdfAccepted Manuscript2.06 MBAdobe PDFThumbnail

Citations 20

Updated on Feb 21, 2024

Web of ScienceTM
Citations 20

Updated on Oct 29, 2023

Page view(s)

Updated on Feb 27, 2024

Download(s) 50

Updated on Feb 27, 2024

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.