Thermal and environmental stability of semi-transparent perovskite solar cells for tandems by a solution-processed nanoparticle buffer layer and sputtered ITO electrode

Thermal and environmental stability of metal halide perovskite solar cells remains a major barrier to their commercialization. The industry standard transparent electrode, ITO, has good optoelectronic properties and high stability. We introduce a robust buffer layer by solution-processing AZO nanoparticles, enabling a sputtered amorphous ITO layer without damaging the underlying device. We make both semitransparent cells (12.3%) and mechanically stacked tandems (12.3% + 5.7% = 18.0%) using monocrystalline-silicon solar cells as the bottom cell. We operate the inverted-architecture, semitransparent perovskite solar cell without additional sealing in ambient atmosphere under one-sun equivalent visible illumination and measure a Ts0 lifetime of 124 hours at 100°C.