Stabilizing high-efficiency perovskite solar cells via strategic interfacial contact engineering
Guixiang Li, Zuhong Zhang, Benjamin Agyei‐Tuffour, Luyan Wu, Thomas W. Gries, Karunanantharajah Prashanthan et al. · 2025 · 123 citationsRead the paper
Abstract Surface passivation in perovskite solar cells can enhance device efficiency, yet incomplete interfacial functionality poses challenges to long-term reliability. Here we present a strategic interfacial engineering approach using sodium heptafluorobutyrate to fully functionalize the perovskite surface. Sodium heptafluorobutyrate acts as an ion shield that tunes the perovskite surface work function and increases the defect formation energy, resulting in an improved interface with the electron transport layer that minimizes recombination and boosts electron extraction under operation. We find that a sodium-heptafluorobutyrate-functionalized perovskite surface promotes a uniform, compact C 60 layer that effectively blocks ion diffusion and stabilizes the device stack. This approach allows p–i–n perovskite solar cells to achieve a record power conversion efficiency (PCE) of 27.02% (certified 26.96% with a maximum-power-point-tracking PCE of 26.61%). Devices with an active area of 1 cm 2 deliver a PCE of 25.95%. Perovskite solar cells retain 100% of their initial efficiency following 1,200 h of continuous 1-sun illumination at the maximum power point. Devices also demonstrate exceptional thermal stability, retaining 92% of the initial PCE when ageing at 85 °C for 1,800 h and 94% after 200 thermal cycles between –40 °C and +85 °C.
What the full text shows
Working prototype- Achieved record power conversion efficiency (PCE) for p–i–n perovskite solar cells. — 27.02% (certified 26.96%) (SHF-treated perovskite surface)
- Maintained initial efficiency under continuous illumination. — 100% retention after 1,200 h (1-sun illumination at maximum power point)
- Maintained efficiency under high-temperature aging. — 92% retention after 1,800 h (85 °C)
- Maintained efficiency during thermal cycling. — 94% retention after 200 cycles (between –40 °C and +85 °C)
- Demonstrated high efficiency on larger active areas. — 25.95% PCE (1 cm2 active area)
- Reduced ion migration (AgI formation) compared to control. — ~2 orders of magnitude lower (Aged devices analyzed via ToF-SIMS)
- Setup
- p–i–n perovskite solar cells (ITO/CbzNaph/perovskite/SHF/C60/BCP/Ag) with active areas of 0.0782 cm2 (certified), 0.0982 cm2, and 1 cm2.
- How
- The researchers applied sodium heptafluorobutyrate (SHF) as a post-treatment surface passivation layer on perovskite films before depositing a C60 electron transport layer. They used DFT calculations, KPFM, and ToF-SIMS to analyze the electronic dipoles, surface work function, and ion diffusion barriers.
- Limitations
- The record PCE was achieved on small-area laboratory cells (approx 0.1 cm2). · The study focuses on a specific p-i-n architecture using C60 as the electron selective contact.
Summarized by Gemma 4 from the open-access full text · 11 Oct 2026. Read it