Fàbrega i Claveria, Ma. CarmeMurcia López, SebastiánMonllor-Satoca, D.Prades García, Juan DanielHernández-Alonso, M.D.Penelas, GermanMorante i Lleonart, Joan RamonAndreu Arbella, Teresa2016-04-282018-02-262016-02-260926-3373https://hdl.handle.net/2445/97985In this work, we present a systematic study on the synthesis of monoclinic gamma - WO3 obtained using pulsed laser deposition (PLD). A photocurrent of 2.4 mA/cm2 (60% of the optical maximum for a 2.7 eV gap material) was obtained for films as thick as 18 micro_m. FE-SEM images revealed that WO3 films were actually formed by an array of oriented columns. Efficient hole extraction towards the electrolyte was observed and attributed to a possible accommodation of the electrolyte between the WO3 columns, even for relatively compact films. This feature, combined with the detailed optical absorption and IPCE characterization, allowed us to implement a double-stack configuration of WO3 photoanodes which resulted in a remarkable photocurrent density of 3.1 mA·cm-2 with 1 sun AM1.5G illumination in 0.1 M H2SO4 electrolyte. Faradaic efficiencies of more than 50% was obtained without co-catalyst, which is one the highest values reported for pure WO3. By adding a 3 nm layer of Al2O3 by ALD, a faradaic efficiency of 80% was reached without diminishing the photocurrent density.8 p.application/pdfengcc-by-nc-nd (c) Elsevier B.V., 2016http://creativecommons.org/licenses/by-nc-nd/3.0/esConversió directa de l'energiaLàsersPel·lícules finesDirect energy conversionLasersThin filmsinfo:eu-repo/semantics/article6613952016-04-28info:eu-repo/semantics/openAccess