Vacuum-made perovskite solar cells hit 27% efficiency in tandem design
Researchers have cracked a manufacturing bottleneck in perovskite solar cells using vacuum deposition—a scalable, solvent-free factory method. The breakthrough delivers certified 18.35% efficiency for single-layer devices and 27.2% for perovskite-silicon tandems, with cells retaining 80% performance after over 1,000 hours of stress testing, positioning the technology closer to commercial viability.
Originaltitel: Crystal-facet-directed all-vacuum-deposited perovskite solar cells
Abstract Vacuum-based deposition is a scalable, solvent-free industrial method ideal for uniform coatings on complex substrates. However, all-vacuum-deposited perovskite solar cells fabricated by thermal evaporation trail solution-processed counterparts in efficiency and stability due to film quality challenges, necessitating advancement and improved understanding. Here, we report a co-evaporation route for 1.67-eV wide-bandgap perovskites by introducing a PbCl 2 co-source to optimize film quality. We promote perovskite formation with pronounced (100) ‘face-up’ orientation and deliver a certified all-vacuum-deposited solar cell with 18.35% efficiency (19.3% in the laboratory) for 0.25-cm 2 devices (18.5% for 1-cm 2 cells). These cells retain 80% of peak efficiency after 1,080 h under the ISOS-L-2 protocol. Leveraging operando hyperspectral imaging, we provide spatiotemporal spectral insight into halide segregation and trap-mediated recombination, correlating microscopic luminescence features with macroscopic device performance while distinguishing radiative from non-ideal recombination channels. We further demonstrate 27.2%-efficient 1-cm 2 evaporated perovskite-on-silicon tandem cells and outdoor stability of all-vacuum-deposited tandems in Italy, retaining ~80% initial performance after eight months.