Interfacial electrostatic phenomena in phthalocyanine Langmuir–Blodgett films

Langmuir–Blodgett films of diazobenzene molecules

“…: (i) the contribution from charge injection changes with the number of layers. This would be consistent with Iwamoto et al who attributed a saturation in the surface potential for copper phthalocyanine LB films [20] and polyimide [41] to a thicknessdependent charge transfer. This hypothesis could be tested employing other metal electrodes, but we have not been able to deposit LB films on aluminum or indium-tin-oxide (ITO) for a direct comparison to be made.…”

“…Considering that the Fermi levels of the SIII are located at the center of the HOMO and LUMO levels, the Fermi level is located at approximately −4.18 eV. The central energy state position between the HOMO and LUMO states of SIII, roughly corresponding to the Fermi energy of SIII, is at an energy state higher than the Fermi levels of Au (4.75 eV) [20]. This suggests that the localized energy state in SIII film tends to donate electrons to the Au electrode [42].…”

“…Though less widespread, the surface potential method has also been applied to Langmuir-Blodgett films [11][12][13][14][15][16], and the modeling is even less straightforward. In addition to depending on the molecular dipole moments, the measured surface potential in LB films depends on various factors such as number of deposited layers [17][18][19], substrate [20], pH [21], and temperature [22]. Early attempts to model surface potentials of LB films considered the films as p-n junctions [23].…”

Kongresse – Symposien – Seminare – Messen

“…Pthalocyanines (Pcs), 18π‐electron heterocyclic conjugated compounds, are used in different technical fields due to their chemical stability and electronic properties 1,2. Also many other applications have appeared recently, including dyes and pigments,3 optical data storage,4 liquid crystals,5 photosensitizers,6 nonlinear optics,7 gas sensors,8 Langmuir‐Blodgett films,9 and catalysis 10. At the same time, pthalocyanines have been investigated for areas such as therapeutic medicine, photodynamic therapy, materials science, catalytic therapy, and antioxidant potentials 11,12.…”