Fig. 3. (a) Schematic illustration and cross-sectional SEM image of a completed device with the architecture of FTO/PEDOT:PSS/perovskite/C60/BCP/Ag. (b) J–V curves of the PSCs. (c) IQE, EQE, reflectance spectra and integrated JSC of the encapsulated champion device under AM1.5G illumination in ambient air, no antireflection technique was applied for the device fabrication. (d) Complex impedance plots of PSCs measured in inert atmosphere under AM1.5G illumination. The shunt resistance across the perovskite layer was estimated at 93, 318, and 550 Ω cm2 for the control, TM-DHP, and both TM-DHP and maltol treated PSCs, respectively. Insert shows the equivalent circuit model for fitting the electrochemical impedance spectroscopy data. (e) The open-circuit voltage VOC as a function of illumination intensity with an ideality factor of 1.62, 1.60, and 1.50 for the control, TM-DHP, and both TM-DHP and maltol treated PSCs, respectively. (f) Dark current–voltage curves of the hole-only devices with the architecture of FTO/PEDOT:PSS/perovskite/PTAA/Ag. PTAA is poly(triaryl amine).
