000201181 001__ 201181
000201181 005__ 20181203023559.0
000201181 0247_ $$2doi$$a10.1021/jp4103614
000201181 022__ $$a1932-7447
000201181 02470 $$2ISI$$a000339930900014
000201181 037__ $$aARTICLE
000201181 245__ $$aElectrochemical Characterization of TiO2 Blocking Layers for Dye-Sensitized Solar Cells
000201181 260__ $$aWashington$$bAmerican Chemical Society$$c2014
000201181 269__ $$a2014
000201181 300__ $$a11
000201181 336__ $$aJournal Articles
000201181 520__ $$aThin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from the substrate (FTO or Ti) with the holeconducting medium at this interface. The quality of blocking is evaluated electrochemically by methylviologen, ferro/ferricyanide, and spiro-OMeTAD as the model redox probes. Two types of pinholes in the blocking layers are classified, and their effective area is quantified. Frequency-independent Mott Schottky plots are fitted from electrochemical impedance spectroscopy. Certain films of the thicknesses of several nanometers allow distinguishing the depletion layer formation both in the TiO2 film and in the FTO substrate underneath the titania film. The excellent blocking function of thermally oxidized Ti, electrodeposited film (60 nm), and atomic-layer-deposited films (>6 nm) is documented by the relative pinhole area of less than 1%. However, the blocking behavior of electrodeposited and atomic-layer-deposited films is strongly reduced upon calcination at 500 degrees C. The blocking function of spray-pyrolyzed films is less good but also less sensitive to calcination. The thermally oxidized Ti is well blocking and insensitive to calcination.
000201181 700__ $$0240197$$aKavan, Ladislav$$g114460$$uAcad Sci Czech Republic, Vvi, J Heyrovsky Inst Phys Chem, CZ-18223 Prague 8, Czech Republic
000201181 700__ $$0244216$$aTetreault, Nicolas$$g187324
000201181 700__ $$0244223$$aMoehl, Thomas$$g196687
000201181 700__ $$0240191$$aGraetzel, Michael$$g105292
000201181 773__ $$j118$$k30$$q16408-16418$$tJournal Of Physical Chemistry C
000201181 909C0 $$0252060$$pLPI$$xU10101
000201181 909CO $$ooai:infoscience.tind.io:201181$$pSB$$particle
000201181 917Z8 $$x105528
000201181 937__ $$aEPFL-ARTICLE-201181
000201181 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000201181 980__ $$aARTICLE