Critical Role of Water in Defect Aggregation and Chemical Degradation of Perovskite Solar Cells

Yun Hyok Kye, Chol Jun Yu, Un Gi Jong, Yue Chen, Aron Walsh

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)

Abstract

The chemical stability of methylammonium lead iodide (MAPbI3) under humid conditions remains the primary challenge facing halide perovskite solar cells. We investigate defect processes in the water-intercalated iodide perovskite (MAPbI3-H2O) and monohydrated phase (MAPbI3·H2O) within a first-principles thermodynamic framework. We consider the formation energies of isolated and aggregated vacancy defects with different charge states under I-rich and I-poor conditions. It is found that a PbI2 (partial Schottky) vacancy complex can be formed readily, while the MAI vacancy complex is difficult to form in the hydrous compounds. Vacancies in the hydrous phases create deep charge transition levels, indicating the degradation of the lead halide perovskite upon exposure to moisture. Electronic structure analysis supports a mechanism of water-mediated vacancy pair formation.

Original languageEnglish
Pages (from-to)2196-2201
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume9
Issue number9
DOIs
Publication statusPublished - 2018 May 3

Bibliographical note

Funding Information:
This work is supported as part of the fundamental research project Design of Innovative Functional Materials for Energy and Environmental Application (No. 2016-20) funded by the State Committee of Science and Technology, DPR Korea. Computations were performed on the HP Blade System C7000 (HP BL460c) that is owned by the Faculty of Materials Science, Kim Il Sung University. A.W. is supported by a Royal Society University Research Fellowship and EPSRC Grant No. EP/K016288/1.

Funding Information:
This work is supported as part of the fundamental research project “Design of Innovative Functional Materials for Energy and Environmental Application” (No. 2016-20) funded by the State Committee of Science and Technology, DPR Korea. Computations were performed on the HP Blade System C7000 (HP BL460c) that is owned by the Faculty of Materials Science, Kim Il Sung University. A.W. is supported by a Royal Society University Research Fellowship and EPSRC Grant No. EP/K016288/1.

Publisher Copyright:
© 2018 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Critical Role of Water in Defect Aggregation and Chemical Degradation of Perovskite Solar Cells'. Together they form a unique fingerprint.

Cite this