000151647 001__ 151647
000151647 005__ 20180317093108.0
000151647 0247_ $$2doi$$a10.1002/adfm.200902060
000151647 022__ $$a1616-301X
000151647 02470 $$2ISI$$a000276775600007
000151647 037__ $$aARTICLE
000151647 245__ $$aControlling Photoactivity in Ultrathin Hematite Films for Solar Water-Splitting
000151647 260__ $$bWiley-Blackwell$$c2010
000151647 269__ $$a2010
000151647 336__ $$aJournal Articles
000151647 520__ $$aA promising route to increase the performance of hematite (alpha-Fe2O3) photoelectrodes for solar hydrogen production through water-splitting is to use an extremely thin layer of this visible light absorber on a nanostructured scaffold. However, the typically poor performance of ultrathin (ca. 20 nm) films of hematite has been the limiting factor in implementing this approach. Here, the surprising effect of a substrate pretreatment using tetraethoxysilicate (TEOS) is reported; it results in drastic improvements in the photoperformance of 12.5 nm thick films of hematite. These films exhibit a water oxidation photocurrent onset potential at 1.1V versus the reversible hydrogen electrode (vs. RHE) and a plateau current of 0.63 mA cm(-2) at 1.5 V vs. RHE under standard illumination conditions, representing the highest reported performance for ultrathin hematite films. In contrast, almost no photoactivity is observed for the photoanode with the same amount of hematite on an untreated substrate. A detailed study of the effects of the TEOS treatment shows that a monolayer of SiOx is formed, which acts to change the hematite nucleation and growth mechanism, increases its crystallinity, reduces the concentration of carrier trapping states of the ultrathin films, and suggests its further application to quantum-dot and extremely-thin-absorber (ETA)-type solar cells.
000151647 6531_ $$aChemical-Vapor-Deposition
000151647 6531_ $$aAlpha-Fe2O3 Electrodes
000151647 6531_ $$aSpray-Pyrolysis
000151647 6531_ $$aMetal-Oxides
000151647 6531_ $$aFerric-Oxide
000151647 6531_ $$aThin-Films
000151647 6531_ $$aPhotoelectrochemical Behavior
000151647 6531_ $$aSemiconductor Electrodes
000151647 6531_ $$aInfrared-Absorption
000151647 6531_ $$aOptical-Properties
000151647 700__ $$0244212$$aLe Formal, Florian$$g178597
000151647 700__ $$0240191$$aGraetzel, Michael$$g105292
000151647 700__ $$0244210$$aSivula, Kevin$$g178220
000151647 773__ $$j20$$q1099-1107$$tAdvanced Functional Materials
000151647 909CO $$ooai:infoscience.tind.io:151647$$particle$$pSB
000151647 909C0 $$0252060$$pLPI$$xU10101
000151647 917Z8 $$x105528
000151647 937__ $$aEPFL-ARTICLE-151647
000151647 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000151647 980__ $$aARTICLE