Lateral inhomogeneity of unoccupied states for PbPc films

► Unoccupied levels of organic films (PbPc) are probed with sub-micrometer resolution. ► The occupied levels are uniform on the annealed sub-monolayer films. ► By contrast, the unoccupied level is significantly inhomogeneous. ► The inhomogeneity arises from the size distribution of nm-clusters. ► The unoccupied level is sensitively affected by neighboring molecules.