I fabricated perovskite solar cells using mixed cations/mixed halide (FA/MA and I/Br) using P-I-N structure with PEDOT:PSS and PCBM. The result shows very high hysteresis and high fill factor in the reversed scans. J-V curve in the reversed scan has a ’dip’ or ”valley-like” characteristic. I need help understanding what is responsible for this valley-like J-V curve.
Also, I believe hysteresis should be less in P-I-N structured devices compared to N-I-P structure and low MA content should minimize ion migration that may be responsible for hysteresis