Simple fabrication of perovskite solar cells with enhanced efficiency, stability, and flexibility under ambient air

In order to increase the applicability and commercial potential of perovskite solar cells, simple fabrication of high-photovoltaic-performance flexible perovskite solar cells with excellent moisture stabilities without the use of a glove-box and an antisolvent is required. In this paper, we present a simple fabrication strategy involving introduction of 4-tert-butylpyridine into CH3NH3PbI3 and significantly enhancing 4-tert-butylpyridine morphology-modifying effect via a reduction-active flexible poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) interlayer. Owing to the specific oxidation facilitation by the poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) polymer, a perovskite film with large (similar to 1 mu m) and quasi-all-in-one-structured grains can be obtained, which significantly enhance the efficiency and the stability of the perovskite solar cells. Furthermore, the high-efficiency flexible perovskite solar cells fabricated by the simple strategy exhibit excellent moisture resistances owing to the stronger coordination and the outside-covering effect of the hydrophobic 4-tert-butylpyridine. The fabrication can be carried out under ambient air (without glovebox, relative humidity > 40%), which paves the way for wearable device application and commercialization.