Fig. 3. Correlative analysis of defects.

AFM topography of vacuum-deposited PTCDA near the film edge (A) and corresponding near-field Φ_NF (1777 cm⁻¹) measured on resonance with the carbonyl mode (B). Scale bars, 500 nm. (C) Histogram constructed from the images (A and B) showing correlation between AFM height and Φ_NF (1777 cm⁻¹). Distinct subpopulations are identified by their statistical correlation and labeled by the colored borders. (D) Spatial map reconstructed from the correlated populations identified in (C) overlaid on AFM height image. Most of the population (green) has the a axis of PTCDA parallel to the surface normal, with smaller populations uplifted with the a axis parallel to the surface normal (light blue), uplifted regions with the a axis oriented away from the surface normal (red), and regions with less coverage and a axis oriented away from the surface normal (yellow). The substrate is shaded dark blue.