6 pages. -- Figure S1. Survey XPS spectra of regions Z1, Z2', Z4', Z5, Z6 and Z8 and of an atomically clean Cu(111) single crystal surface reference. -- Figure S2. High-resolution XPS spectra corresponding to the (a) C1s and (b) O1s core levels of regions Z1, Z2', Z4', Z5, Z6 and Z8. -- Fig S3. General diffraction pattern extracted from bidimensional detector for each zone labelled in inset picture. -- Figure S4. Finite element mapping in COMSOL main cell configuration according to the two mesh sizes described in Table S1. -- Table S1. Comsol parameters used in calculations.

ICN2 is funded by the CERCA program/Generalitat de Catalunya.

Peer reviewed