Why Flexibility Matters
Where the Efficiency Records Now Sit
Stability: The Persistent Obstacle
The Lead Question
Outlook
References and Further Reading
For most of the solar industry's history, a “solar panel” has meant a rigid, glass-faced module bolted to a roof or mounted on a field rack. That picture is changing. Flexible perovskite solar cells (f-PeSCs), thin-film devices built on bendable plastic, metal foil, or barrier-coated substrates, are an alternative for applications where weight, curvature, and low-temperature fabrication matter as much as raw efficiency.1
Image Credit: Audio und werbung/Shutterstock.com
A comprehensive bibliometric review published in Energy Advances in 2026 mapped more than 3,000 papers on f-PeSCs published between 2012 and 2024, and the numbers tell a striking growth story.1 In that period, the certified power conversion efficiency (PCE) of f-PeSCs under standard AM1.5G sunlight rose from around 2.6% to roughly 24.7%. Under indoor lighting conditions, record devices reached 41% PCE by 2024, well above the approximately 26.7% ceiling recorded for outdoor rigid perovskite cells that same year.1 The same analysis projects the global f-PeSC market to expand from about US$0.35 billion in 2023 to US$8.81 billion by 2034, a steeper growth curve than the broader solar cell market, which is projected to roughly quintuple over the same period.1
Want to save for later? Click here.
Why Flexibility Matters
Unlike silicon wafers, which require high-temperature processing and rigid glass encapsulation, perovskite absorber layers can be deposited from solution at temperatures below 150 °C.1 This compatibility with low-temperature routes allows the active layer to be built directly on plastics such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), on polyimide (PI) for higher-temperature applications, or on thin stainless-steel and titanium foils where opacity is not a barrier.1 Each substrate involves trade-offs: PET is inexpensive but limited to roughly 70–80 °C during processing, PEN tolerates around 120 °C, and PI withstands temperatures above 300 °C but costs considerably more and carries a yellow tint that reduces optical transparency.1
This substrate versatility opens applications that rigid modules cannot serve: building- and vehicle-integrated photovoltaics on curved surfaces, wearable and skin-mounted power sources, self-powered Internet of Things (IoT) sensors, and even aerospace structures.1
A related review in Nano Convergence tracked annual efficiency records for flexible photovoltaics from 2015 to 2024, showing PCE climbing from around 6% to more than 26%, alongside a corresponding rise in published output that reflects intensifying commercial interest.2
Where the Efficiency Records Now Sit
Several results reported in 2024 and 2025 illustrate how quickly the field is moving. Researchers at the Korea Institute of Energy Research reported a flexible perovskite/CIGS tandem cell reaching 23.64% PCE, using a lift-off process that fabricates the device on rigid glass before transferring it onto a flexible polyimide layer, improving film uniformity relative to direct deposition on plastic.3
A separate flexible perovskite/silicon tandem cell achieved a certified 33.6% efficiency with a record open-circuit voltage of 2.015 V, while retaining 91% of its initial output after 5,000 bending cycles at a 17.6 mm bend radius and passing 1,000 hours of damp-heat testing.4
For single-junction flexible devices specifically, a porous electron transport layer design pushed the standalone outdoor record to 20.7% in 2024, narrowing the long-standing performance gap with rigid cells.5 Indoor-specific devices have gone further still, with reviews reporting flexible perovskite cells exceeding 40% PCE under artificial light between 100 and 1,000 lux, a niche where the tunable bandgap of perovskites gives them a natural advantage over silicon.6,7
Stability: The Persistent Obstacle
Efficiency figures alone do not determine commercial viability. Moisture is the most damaging factor for perovskite films, triggering hydration reactions that can cut PCE by 20–30% after 1,000 hours of standard-condition operation, while UV exposure combined with humidity can reduce output by up to 65% within a few weeks.1
Repeated bending introduces its own failure modes, including microcracking at grain boundaries and delamination between layers, with losses of 15–25% reported after roughly 2,000 bending cycles at a 3.5 mm curvature radius.1
Encapsulation strategies, inorganic barrier films of aluminum oxide or silicon nitride, hybrid organic–inorganic multilayer coatings, and self-healing polymer additives remain the main line of defense, and some formulations now maintain over 90% of initial efficiency after thousands of operating hours or bending cycles.1
The Lead Question
Most high-efficiency perovskites rely on lead halides, and the toxicity of soluble lead compounds remains one of the field's most cited barriers to large-scale deployment.8
Tin-based lead-free perovskites are the most extensively studied alternative, with certified efficiencies rising from under 1% in 2012 to about 15.7% by 2024, although Sn²+ oxidizes readily to Sn4+, undermining long-term stability.8
Antimony-, bismuth-, and germanium-based perovskites offer better chemical stability but currently trail well behind tin- and lead-based systems in efficiency.8
A parallel strategy, mixed tin-lead formulations, has reached certified efficiencies above 24% for single-junction cells and beyond 28% in tandem architectures, offering a partial reduction in lead content without a comparable loss of performance.9 Encapsulation and lead-sequestration coatings are also being explored specifically to limit lead leaching if a damaged module is exposed to water.10
Outlook
Roll-to-roll manufacturing, slot-die and blade coating, and inkjet printing are already being used to scale f-PeSC production beyond the laboratory bench, and several groups have demonstrated modules of tens of square centimeters retaining double-digit efficiencies.1
With efficiency, cost, and market indicators all moving in the same direction, the central technical questions for flexible perovskite solar cells are shifting from whether they can compete with silicon toward how quickly stability and lead-toxicity concerns can be resolved at industrial scale.1,11
References and Further Reading
- Santos, T. F., Santos, C. M., Kumar, V. V., et al. (2026). Flexible perovskite solar cells: Materials design, environmental stability, and sustainable strategies for all-environment photovoltaics. Energy Advances, 5, 898–927. https://doi.org/10.1039/D5YA00363F
- Flexible perovskite solar cells: Advancements in materials, fabrication techniques, and future prospects. (2025). Nano Convergence. https://doi.org/10.1186/s40580-025-00524-y
- Korea Institute of Energy Research. (2024). Ultralight, flexible perovskite/CIGS tandem solar cells set new efficiency record at 23.64%. Joule. (Reported in Tech Xplore). https://doi.org/10.1016/j.joule.2024.11.011
- Flexible perovskite/silicon tandem solar cells with 33.6% efficiency. (2025). Nature. https://www.nature.com/articles/s41586-025-09849-4
- New record efficiency for flexible perovskite solar cells. (2024, June 10). Chemistry World. https://www.chemistryworld.com/news/new-record-efficiency-for-flexible-perovskite-solar-cells/4012858.article
- Review of flexible perovskite solar cells for indoor and outdoor applications. (2024). Materials for Renewable and Sustainable Energy. https://doi.org/10.1007/s40243-024-00257-8
- Recent progress on perovskite based indoor photovoltaics: Challenges and commercialization. (2024). Solar Energy. https://www.sciencedirect.com/science/article/abs/pii/S0038092X24007448
- Stability of lead-free perovskite solar cells. (2026). Advanced Sustainable Systems. https://doi.org/10.1002/adsu.202600008
- Huang, C., Huang, Y., Zhao, Q., et al. (2026). Eco-friendly lead-free and low-lead perovskite solar cells. Energy Materials and Devices, 4(1), Article 9370089. https://doi.org/10.26599/EMD.2026.9370089
- Miah, Md. H., Khandaker, M. U., Hossen, Md. J., et al. (2025). Lead-free alternatives and toxicity mitigation strategies for sustainable perovskite solar cells: A critical review. Materials Advances, 6, 2718–2752. https://doi.org/10.1039/D5MA00010F
- Perovskite solar cells: Progress continues in efficiency, durability, and commercialization. (2025, March 18). The American Ceramic Society. https://ceramics.org/ceramic-tech-today/perovskite-solar-cells-progress-2025/
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.