Abstract
Impressive progress in halide perovskite solar cells motivates further work to improve operating stability. It is known that ion-migration-driven decomposition represents a degradation pathway in perovskite solar cells and that it can occur within the perovskite material even in well-encapsulated devices. Here we find that quasi-two-dimensional (2.5D) perovskites suppress this ion-migration-induced degradation. Using TOF-SIMS, we confirm that iodide migration occurs in bulk perovskite photovoltaic devices operating at their maximum power point (MPP). We observe that iodine ions migrate across the spiro-OMeTAD layer to the spiro/gold contact interface, oxidizing and deteriorating the gold at the interface. In contrast, we find that large n»2.5D perovskites exhibit a significantly reduced rate of ion migration compared to 3D devices and exhibit less than 1% relative PCE loss in over 80 h of continuous operation at MPP, whereas the PCE of 3D devices diminishes by more than 50% within the first 24 h.
Original language | English (US) |
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Pages (from-to) | 1521-1527 |
Number of pages | 7 |
Journal | ACS Energy Letters |
Volume | 4 |
Issue number | 7 |
DOIs | |
State | Published - Jun 10 2019 |
Funding
This publication is based on work supported by the U.S. Department of the Navy, Office of Naval Research (Grant Award No.: N00014-17-1-2524). M.I.S. acknowledges the support of the Banting Postdoctoral Fellowship Program, administered by the Government of Canada. A.H.P. acknowledges support from the NSERC Alexander Graham Bell Scholarship program. The authors thank Dr. P. M. Brodersen in the Ontario Centre for Characterization of Advanced Materials (OCCAM) for assistance with materials characterization using TOF-SIMS and XPS.
ASJC Scopus subject areas
- Chemistry (miscellaneous)
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Materials Chemistry