- Sub-1.4eV bandgap inorganic perovskite solar cells with long-term stability.
Sub-1.4eV bandgap inorganic perovskite solar cells with long-term stability.
State-of-the-art halide perovskite solar cells have bandgaps larger than 1.45āeV, which restricts their potential for realizing the Shockley-Queisser limit. Previous search for low-bandgap (1.2 to 1.4āeV) halideĀ perovskites hasĀ resulted in several candidates, butĀ all are hybrid organic-inorganic compositions, raising potential concern regarding device stability. Here we show the promise of an inorganic low-bandgap (1.38āeV) CsPb0.6Sn0.4I3 perovskite stabilized via interfaceĀ functionalization. Device efficiency up to 13.37% is demonstrated. The device shows high operational stability under one-sun-intensity illumination, with T80 and T70 lifetimes of 653āh and 1045āh, respectivelyĀ (T80 and T70 represent efficiency decays to 80% and 70% of the initial value, respectively), and long-term shelf stability under nitrogen atmosphere. Controlled exposure of the device to ambient atmosphere during a long-term (1000āh) test does not degrade the efficiency. These findings point to a promising direction for achievingĀ low-bandgap perovskite solar cells with high stability.