Fig. 4: Heatmaps of film deposition parameters showing optimal concentration and mass load for homogeneous film formation.
From: Layer-by-layer assembly yields thin graphene films with near theoretical conductivity
A Graph showing optical scans of the films formed for the ink optimisation study, with the ink concentrations (g/L) and areal mass load of nanosheets on the interface (g/m2) shown. B Heatmap of film coverage of each of the films formed, showing that lower areal mass loads lead to incomplete films. C Heatmap of film thickness homogeneity (ratio of the mean film thickness and film thickness standard deviation, extracted from ratio of mean extinction <Ext>film and extinction standard deviation ΔExtfilm), showing high areal mass load, low ink concentration to yield films with best thickness homogeneity. D Heatmap of relative film perimeter, showing that only high areal mass load and low concentration yields films with completely contiguous films. E Heatmap of film conductivity homogeneity (ratio of the mean film conductivity <σ>film and the average uncertainty in film conductivity Δσfilm) measured by the transmission line method, showing that high areal mass load, low ink concentration yields films with the best film conductivity homogeneity. F SEM image of a film with medium concentration and low areal coverage (0.0939 g/L 6.9 g/m2), showing discontinuities on the microscale, and (G) SEM image of a film with high concentration and high areal coverage (0.543 g/L 21 g/m2), showing the formation of aggregated, inhomogeneous structures on the microscale.
