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Abstract Organic‐inorganic hybrid perovskite solar cells are susceptible to multiple influencing factors such as moisture, oxygen, heat stress, ion migration. Given the complex practical working conditions for solar cells, a fundamental question is how different failure mechanisms collaborate and substantially accelerate the device degradation. In this study, it is found that ion migration can accelerate the reaction between oxygen and methylammonium lead iodide perovskite in light conditions. This is suggested since regions with local electric fields suffer from more severe decomposition. Here it is reported that cesium ions (Cs+) incorporated in perovskite lattice, with a moderate doping concentration (e.g. 5%), can function as stabilizers to efficiently interrupt such a synergistic effect between oxygen induced degradation and ion migration while retaining the high performance of perovskite solar cells. Both experimental and theoretical results suggest that 5% Cs+ions incorporation simultaneously suppresses the formation of reactive superoxide ions () as well as ion migration in perovskites by forming additional energy barriers. This A‐site cations engineering is also a promising strategy to circumvent the detrimental effect of oxygen molecules in FA‐based perovskites, which is important for developing high‐efficiency perovskite solar cells with enhanced stability.
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Temperature‐ and Bias‐Dependent Degradation and Regeneration of Perovskite Solar Cells with Organic and Inorganic Hole Transport Layers
Hybrid halide perovskite solar cells have drawn widespread attention with the achievement of high power conversion efficiencies. However, poor stability remains the greatest barrier preventing their commercialization. Performance degradation and recovery have a complicated dependence on the environment and a dependence on the applied bias, which affects ion migration. Herein, solar cells with an organic hole transport layer and cells with an inorganic hole transport layer are compared. A type of degradation of the organic transport layer is examined, which is reversible by applying a forward bias soak, and how the degradation arises from ion migration mechanisms is explained. Experimental current–voltage and capacitance transient measurements are conducted as a function of temperature. The resulting S‐kink and positive capacitance decay are explained in terms of the modeled effects of a changing ion density at the hole transport layer. An irreversible degradation is found upon heating to more than 100 °C. On the contrary, the inorganic hole transport layer is found to eliminate the observable effects of ion migration, even at elevated temperatures, so long as air exposure is avoided.
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- Award ID(s):
- 1906492
- PAR ID:
- 10258868
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- physica status solidi (a)
- Volume:
- 218
- Issue:
- 7
- ISSN:
- 1862-6300
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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