Fig. 5. (a) Light intensity dependent JSC of air-annealed (blue solid squares) and N2-annealed (red solid circles) perovskite solar cells (using an illumination wavelength of 730 nm). A black line with an exponent α = 1 is added as a visual aid. (b) Light intensity dependent VOC of air annealed (blue squares) and N2 annealed (red circles) perovskite solar cells measured using two different illumination wavelengths (730 nm solid symbols and 405 nm open symbols). The ideality factors (n) calculated from the slopes of linear fit lines to the higher light intensity linear parts of the curves are n ≈ 1 for N2-annealed cells and n ≈ 1.3 for air-annealed cells.
