Fig. 2: The chemical constituent distributions as a function of sputtering time.
From: Tracking the evolution of materials and interfaces in perovskite solar cells under an electric field
a The relative concentration of Pb and I for the samples with and without electric stress (±1 V). The data points are based on two sets of samples. The sample-to-sample uncertainty is ±0.7% (0 V), ± 0.4% (−1 V) and ±0.4% (+1 V), respectively (seen in Supplementary Table 3). The dashed gray dash line represents the I stoichiometric ratio for the PbI2. b The molar ratios of the chemical constituents extrapolated from the elemental depth profile in Fig. 1b–d. c Schematic diagram of mobile species throughout the multilayer stacks consisting of perovskite/PCBM/BCP/Cu. Mobile species such as PbI2 and I2 are marked as well.
