XPS and UPS characterization of the TiO2/ZnPcGly heterointerface: Aligmment of energy levels
2002 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 106, no 23, 5814-5819 p.Article in journal (Refereed) Published
The electronic structure and the highest occupied molecular orbitals (HOMO)/the lowest unoccupied molecular orbitals (LUMO) alignment at the molecular semiconductor heterointerface of nanostructured TiO2/ZnPcGly dye sensitizer were characterized by X-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The HOMO level of the dye ZnPcGly was determined to be located at 1.62 eV below the Fermi edge, and the corresponding LUMO level was estimated to be 0.10 eV above the conduction band of TiO2 based on the HOMO/LUMO gap (1.82 eV) of ZnPcGly determined by optical absorption measurements. This energy level matching between the orbitals of the dye and the bands of TiO2 can enable efficient electron transfer from photoexcited ZnPcGly to TiO2, which is very important in photoinduced charge-transfer reactions and for applications in dye-sensitized solar cells.
Place, publisher, year, edition, pages
2002. Vol. 106, no 23, 5814-5819 p.
sensitized solar-cells, tio2 films, surface, spectroscopy, phthalocyanines, photoemission, electrode, molecules, tio2(110), injection
IdentifiersURN: urn:nbn:se:kth:diva-21615ISI: 000176161900003OAI: oai:DiVA.org:kth-21615DiVA: diva2:340313
QC 201005252010-08-102010-08-10Bibliographically approved