Effect of Modulating Spin-Coating Rate of TiO₂ Precursor for Mesoporous Layer on Hysteresis of Solar Cells with Polar CH₃NH₃PbI₃ Perovskite Thin Film

Figure 5

PFM phase images of the CH₃NH₃PbI₃ perovskite films which applied (~8 V, +3 V) (a) w/o mp-TiO₂ layer and with the spin-coating rate of the mp-TiO₂ precursor for (b) 3000 rpm and (c) 1500 rpm. PFM phase images of the CH₃NH₃PbI₃ perovskite films which applied (~8 V, +6 V) (d–f) correspond to those which applied (~8 V, +3 V) without mp-TiO₂ layer and with the different spin-coating rates of the mp-TiO₂ precursor.

(a)

(b)

(c)

(d)

(e)

(f)