Stability of Tin-Lead Halide Perovskite Solar Cells

Conference · Thu Feb 06 04:00:00 EST 2020

DOI:https://doi.org/10.1109/PVSC40753.2019.8980810· OSTI ID:1604591

Prasanna, Rohit ^[1]; Raiford, James A. ^[2]; Leijtens, Tomas ^[1]; Dunfield, Sean ^[1]; Wolf, Eli J ^[1]; Swifter, Simon A. ^[2]; Eperon, Giles E ^[1]; de Paula, Camila ^[3]; Palmstrom, Axel ^[1]; Van Hest, Marinus F ^[1]; Bent, Stacey F. ^[2]; Teeter, Glenn R ^[1]; Berry, Joseph J ^[1]; McGehee, Michael D. ^[4]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2. Stanford University
3. Swift Solar
4. University of Colorado

Tin-lead perovskites have low band gaps (1.2 eV - 1.4 eV) that offer complementary absorption spectra to mixed halide perovskites with band gaps in the range of 1.6 eV - 1.85 eV. In combination, tin-lead and mixed halide perovskites can be used to make efficient all-perovskite tandem solar cells. While these can achieve high efficiency, they are hampered by the unproven longterm stability of tin-containing perovskites. We make the first demonstration of tin-lead perovskite solar cells that pass benchmark 1000-hour tests of stability under stressors of heat, light, and atmospheric exposure. We identify that mixed tin-lead perovskites oxidise by a different chemical pathway, one that is much less favourable, than the oxidation pathway followed by pure tin perovskites, making them significantly more stable. Fortuitously, mixed tin-lead perovskites also have band gaps that are close to ideal for the rear cell of an all-perovskite monolithic two-junction tandem. Beyond selecting the composition of the perovskite to be one that has inherently suppressed tendency to oxidise, we also fabricate a novel heterojunction-based architecture that eliminates the commonly used acidic PEDOT:PSS layer, which leads to enhanced stability. By packaging the resulting solar cell in a glass-on-glass package with a pliable low-elastic-modulus polyolefin encapsulant and a butyl rubber edge seal, we also demonstrate that the low band gap perovskite solar cell that passes the IEC damp heat test for thin film solar cells - a milestone that demonstrates the removal of a significant impediment to the commercialization of high efficiency perovskite tandem solar cells.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1604591
• Report Number(s): NREL/CP-5900-76332
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
energy gap
organic semiconductors
solar cells
tin compounds