Thermal flow air post-treatment under high relative humidity for efficient and reproducible planar CH 3 NH 3 PbI 3−x Cl x based perovskite solar cells

We report the effects of thermal flow air post-treatment on the performance of solution-processed CH 3 NH 3 PbI 3−x Cl x based planar solar cells under high relative humidity. It is found that the treatment process results in a significant enhancement in the power conversion efficiencies from 7.06 to 10.42%. The fill factor can be controlled in more than 0.7, with low values of the standard deviations. The change of shunt resistance and series resistance reflect that a high relative humid environment may be conducive to form good interfacial contact and decrease contact resistance of device, further enhance charge carrier lifetime among the layers interface, thus improving photovoltaic performance. Moreover, the PL intensity variations indicate that the appropriate temperature of thermal flow air post-treatment reducing the recombination of localized excitons of perovskite film, hence enhancing the charge separation and transport capability. Utilizing appropriate temperature thermal flow air post-treatment under high relative humidity, high efficiency solar cells with good reproducibility were achieved.