Synthesis of mesoporous ITO/TiO2 electrodes for optoelectronics

Several optoelectronic applications require transparent and conductive films, usually deposited by RE-magnetron sputtering, interfaced with a TiO2 compact or mesoporous layer, deposited in subsequent processes. Here we report on the direct fabrication by RF-magnetron sputtering of mesoporous ITO/TiO2 heterojunctions, exhibiting enhanced charge-transfer properties. The mesoporous morphology was obtained by tuning the sputtering deposition parameters. Scanning Electron Microscopy provided a deeper insight into the electrode building, which resulted composed by a compact ITO layer, tapered with columnar ITO nanocrystals, completely covered with jagged anatase TiO2 cauliflower-like structures. Such mesoporous electrodes exhibited enhanced electrochemical performances, compared to those of compact thin-film heterojunctions, due to the enhanced charge transfer at the ITO/TiO2 interface. (C) 2014 Elsevier B.V. All rights reserved.