Power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has already soared from 3.8% to more than 26%. Their potential for application in tandem architecture with silicon and other established solar technologies has been deemed the future of low-cost solar technology. However, the commercialization of this technology is critically limited by instability under operational and environmental stress. The instability in the PSCs stems from both internal mechanisms including ion migration, defect formation, and electrode or charge transport layer (CTL)-induced degradation as well as external stressors such as moisture, oxygen, heat, and illumination. A complete understanding of both the internal and external stimuli-induced degradation and their mitigation strategies is essential for improving the device’s longevity. This review aims to provide a complete overview of the degradation mechanisms and steps taken to mitigate the degradation issues. The first half of the review discusses the degradation mechanism caused by internal degradation factors and provides strategies to mitigate them, while the second half focuses on the external stressors and the approaches developed by the perovskite community to overcome them. The commercialization of PSCs will depend on a holistic approach that simultaneously ensures both intrinsically as well as extrinsically stable devices.

Doping lithium into nickel oxide not only improves its electrical conductivity but also facilitates lithium-ion diffusion into the perovskite, enhancing the quality of the absorber and, consequently, the performance of the solar cell.

Morphology-controlled nanostructures provide an effective strategy to modulate both oxygen evolution reaction (OER) activity and photovoltaic performance in perovskite solar cells (PSCs).

Inverted perovskite solar cells (PSCs) have gained significant attention due to their ease of fabrication and superior stability. Surface passivation has proven to be an effective strategy for mitigating defect densities and suppressing non-radiative recombination at the perovskite-electron transport layer (ETL) interface. However, conventional single-passivant strategies often fail to simultaneously enhance both efficiency and long-term stability. Here, we introduce a dual-passivation approach using ethylene diammonium diiodide (EDAI) and dimethyl ethylene diammonium diiodide (DEDAI) to achieve improved device performance and durability. This synergistic passivation not only addresses undercoordinated lead ions and halide vacancies but also leverages the methyl-functionalized groups in DEDAI to create a moisture-resistant barrier, thereby enhancing the stability of the underlying perovskite layer. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) measurements confirm that the dual-passivated perovskite surface exhibits superior defect passivation compared to single-molecule treatments. Furthermore, this approach promotes enhanced crystallinity and smoother surface morphology, facilitating more efficient electron transport toward ETL and ultimately boosting device performance. With this strategy, the power conversion efficiency (PCE) of our inverted PSCs improved significantly, rising from 17.6% in control devices to 18.4% with single passivation, and further to 19.5% with dual passivation. The shelf life of the solar cells also enhanced upon dual passivation.