Fig. 2: Surface morphology, potential, and the local density of states.
From: Stabilization of highly efficient perovskite solar cells with a tailored supramolecular interface
a AFM topography of the control film and those with HG or DHG treatments. b Work function (WF) maps of (a). The red dotted circles represent precipitations occurring after the different treatments of the control sample. c Grain boundary band bending of all samples (work function difference between grains and grain boundaries). d Average scanning tunneling spectroscopy curves of the samples. A linear extrapolation (dotted lines) of the normalized and broadened LDOS curves was used to estimate the surface bandgap. e LDOS plotted on a log scale, exhibiting a defect signature for the control sample, which is suppressed on the other samples.
