Fig. 4. Stabilized J–V curves (a) and EQE spectra (b and c) of perovskite solar cells spin coated in N2 using the hot cast method and annealed in dry air and humid N2 as indicated in the legends. Black squares depict the EQE under low charge carrier density (i.e. without bias illumination), green circles depict the EQE at a charge carrier density similar to that of the cell under 1 sun light intensity (i.e. with bias illumination). The integrated current density is displayed in the graphs for both measurements.
