Effective methods for improving device performances of P-I-N perovskite solar cells

In this presentation, we report a simple and effective method for improving the performance of CH₃NH₃PbI₃ perovskite solar cells. By employing a novel hot-air annealing process (HAAP) and a merged annealing method (MA) for preparing the perovskite CH₃NH₃PbI₃ film, we could successfully enhance the crystallinity of the CH₃NH₃PbI₃ active layer and improve its photon collection properties. This led to a marked improvement in device performance. Solar cells with the structure indium tin oxide/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/CH₃NH₃PbI₃ active layer/[6,6]-phenyl-C61-butyric acid methyl ester/Ca/Al and fabricated using these methods showed significantly improved performance, including higher PCE and fill factor values than those of the device fabricated conventionally. The PCE increased from 9.05 to 15.55 % when the HAAP process was used and to 18.55 % when the MA was used. Moreover, the devices did not exhibit photocurrent hysteresis, which is always observed in the case of the conventionally fabricated solar cells owing to the charge traps resulting from the low quality of the perovskite film.