Figure 4

Experimental determination of the HOMO and LUMO energy levels of the N719 dye.
(a) UPS pattern of N719 indicating the HOMO energy level of −5.34 eV below the vacuum level, (b) Normalized UV-visible absorption spectrum of N719 in ethanol which provides an estimation of the band gap of N719 and (c) Cyclic voltammograms of the N719 dye in DMF measured at a scan rate of 50 mV/s.