Extended Data Fig. 3: Characterization of TEPL and tautomerization.
a-c, TEPL intensity (orange rectangles) and tautomerization frequency (grey circles) of H2Pc recorded as a function of the laser power for three different excitation energies. All measurements are recorded at the extremity of a pyrrole unit. Integration range of the TEPL spectra: 1.79-1-82 eV, V = 0.55 V, current set-point I = 2 pA, the light intensity is corrected for the detection efficiency. The solid lines are linear fits to the data. d, PLE spectra recorded for two different laser beam alignments that are optimized for 1.82 eV and 1.84 eV excitation energy, respectively. The feature that corresponds to the Qx resonance (1.81 eV) is clearly visible on top of the broad distribution that is centred around the optimal excitation wavelength. The traces are vertically offset for clarity. P < 1μW, I = 10 pA, V = 0.55 V. e, TEPL spectra recorded on a decoupled H2Pc molecule (black line) on NaCl/Ag(111) (V = 0.55 V) and on clean (grey line) NaCl/Ag(111) (V = - 1 V). hνin = 1.953 eV, P ≈ 15μW, I = 2 pA, t = 90 s. The longpass filter (LPF) edge is indicated. f, Background-corrected TEPL spectrum.