Artemisinin (ART)-Induced “perovskite/perovskite” bilayer structured photovoltaics

Halide perovskites have attracted significant attention due to their high photovoltaic (PV) performance. The transition of perovskite PVs into practical applications will require significantly higher reliability while maintaining high efficiency. Here we provide breakthroughs in achieving this goal of enhanced efficiency and reliability. A medical molecular additive, artemisinin (ART), is found to result in the spontaneous formation of a “perovskite/perovskite” bilayer structure during the film casting process. The top-perovskite-layer shows up-shifted Fermi level resulting in an excellent electron blocking effect (EBE) responsible for a high open-circuit-voltage. Further, this bilayer structure enhances hydrophobicity due to the nanoscale wrapping by ART molecules. Combined, “perovskite/perovskite” bilayer results in reliable PV cell with simultaneously improved efficiency (20.43% versus 18.28% from control cell) and stability (95% efficiency was preserved after one-month ambient exposure). These promising results demonstrate that medical biomolecule engineered PVs could pave a new perspective to reliable PV implementation.