Electrochemical investigation of traps in a nanostructured TiO2 film
2001 (English)In: Journal of Physical Chemistry B, ISSN 1089-5647, Vol. 105, no 13, 2529-2533 p.Article in journal (Refereed) Published
Electron traps at the nanostructured TiO2 (anatase)/aqueous electrolyte interface have been studied by means of electrochemical methods. The transient current decays at different potentials positive of the flat band potential clearly illustrate the trap-filling process. The more negative the potential, the shorter the trap-filling period. It is found that most traps locate positive of -0.9 V vs Ag/AgCl at pH 13, or positive of -0.3 V vs Ag/AgCl at pH 4.7. It is proposed that the trap distribution as a function of potential is directly proportional to dQ/dU, i.e., to the current density in a linear sweep voltammetry experiment. The trap densities in aqueous electrolytes are estimated to be 4 x 10(11) cm(-2) (microscopic area) at pH 4.7 and 5 x 10(13) cm(-2) (microscopic area) at pH 13. The pH dependency of the trap density indicates that traps investigated are surface-related.
Place, publisher, year, edition, pages
2001. Vol. 105, no 13, 2529-2533 p.
titanium-dioxide films, nanocrystalline semiconductor-films, charge recombination kinetics, colloidal tio2, solar-cells, photocurrent transients, electronic transport, band energetics, spectroscopy, particles
IdentifiersURN: urn:nbn:se:kth:diva-20508ISI: 000167928000009OAI: oai:DiVA.org:kth-20508DiVA: diva2:339203
QC 201005252010-08-102010-08-10Bibliographically approved