Researchers have demonstrated that accelerated aging tests using increased light intensity and electrical bias can replicate the spatially non-uniform degradation modes observed in outdoor-aged perovskite solar cells, linking field degradation to mechanism-targeted aging strategies.
Study: Accelerated aging replicates spatially non-uniform degradation modes observed in outdoor-aged perovskite solar cells. Image Credit: Taylan Celik/Shutterstock.com
Real-world PSC Degradation Modes
The commercialization of advanced solar cell technologies hinges critically on their ability to maintain long-term stability under real-world conditions. While perovskite solar cells (PSCs) are promising photovoltaic devices due to their high efficiencies and low production costs, their operational durability remains a challenge for large-scale deployment.
Existing standardized aging protocols provide important benchmarks; however, accurately replicating degradation phenomena that occur during extended outdoor use has been elusive. Such a gap hinders the prediction of long-term performance and the formulation of targeted mitigation strategies.
This research addresses a pressing need for a better understanding of the complex, spatially heterogeneous degradation modes that perovskite solar cells experience when deployed outdoors over extended periods. Recognizing and reproducing these degradation pathways under accelerated laboratory conditions can offer faster lifetime assessments and direct efforts to enhance device durability.
The study focuses on linking degradation modes identified in field-aged devices to controlled stress conditions in the laboratory, building toward reliability tests that address the underlying mechanisms rather than solely the aggregate performance loss.
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Controlled Stressor Aging Protocols
The analysis began with the examination of perovskite solar cells subjected to 20 months of real-world outdoor operation in Berlin, Germany. These devices incorporated a mixed-cation and mixed-halide perovskite absorber layer, representative of state-of-the-art compositions.
Using a suite of spatially resolved characterization tools, including hyperspectral photoluminescence (PL) microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), confocal laser scanning microscopy (CLSM), and two-dimensional X-ray diffraction (2D-XRD), the researchers identified and spatially mapped degradation features across the active area.
To replicate the aging phenomena observed outdoors, accelerated aging tests were conducted under controlled laboratory conditions. The primary variables manipulated were light intensity (comparing 1 sun and 2.3 suns) and electrical bias conditions (operating at the maximum power point [MPP] versus open-circuit [OC]).
The sample temperature was carefully regulated at approximately 35 °C during illumination to isolate effects related to light and bias. By systematically varying these parameters, the study disentangled the roles of different stressors in activating specific degradation modes.
The laboratory-aged devices were subjected to chronic illumination and biasing, and their evolving morphology and optoelectronic properties were characterized using the same spatially resolved techniques applied to outdoor-aged cells. This parallel approach permitted direct mechanistic comparisons.
Spatial Degradation Mechanism Insights
After extended outdoor exposure, three distinct degradation modes were identified in perovskite solar cells: copper corrosion near electrodes, edge-related damage linked to device design, and phase segregation within the perovskite absorber.
Phase segregation was the dominant intrinsic mechanism, forming micrometer-scale domains with altered photoluminescence and irreversible structural changes, driven by cation migration and lattice strain. Copper corrosion and edge patterns originated from electrode interfaces and peripheral stresses, respectively.
Accelerated aging experiments reproduced these modes, showing that increasing light intensity from 1 to 2.3 suns caused a superlinear degradation rate increase (~5.8×), enabling an estimated T_80 lifetime of ~15.6 months, consistent with outdoor data.
However, indoor tests at 1 sun under constant maximum power point bias lacked the spatial extent of phase segregation seen outdoors, highlighting the critical impact of outdoor thermal fluctuations (up to 40 °C) that exacerbate ion migration via strain.
Electrical biasing also influenced degradation, with forward bias in the dark accelerating phase segregation, demonstrating electrical stress as a key factor. Spatially resolved analyses, including detection of cesium-enriched regions and diffraction patterns, revealed complex chemical rearrangements.
These findings support strategies targeting ion migration suppression to enhance stability, advocating mechanism-focused aging tests and localized characterization for reliable device durability assessment.
Mechanism-Driven Aging Perspectives
This study links real-world degradation in perovskite solar cells (PSCs) with accelerated lab aging, establishing a framework for lifetime prediction through mechanism-targeted stress tests. Three degradation modes were identified: copper corrosion, edge damage, and phase segregation.
Among these, phase segregation, driven by cation migration and intensified by thermal and electrical stress, is the primary intrinsic degradation pathway and a key focus for stabilization. Accelerated aging under increased illumination and controlled electrical bias effectively replicates outdoor damage, allowing rapid material and design screening.
The results emphasize the need for stability evaluations beyond overall performance loss, advocating spatially resolved analyses of degradation mechanisms. Incorporating temperature variations and complex outdoor factors into aging protocols is essential for accurate lifetime predictions.
By experimentally correlating field and lab degradation, this work advances understanding of degradation mechanisms and supports the rational design of more stable PSCs, accelerating their deployment in sustainable energy technologies.
Journal Reference
Erdil, U., Bergenholtz, L. et al. (2026). Accelerated aging replicates spatially non-uniform degradation modes observed in outdoor-aged perovskite solar cells. Joule, 10, 102538. DOI: 10.1016/j.joule.2026.102538, https://www.cell.com/joule/fulltext/S2542-4351(26)00222-9