Synthesis of mesoporous ITO/TIO2 electrodes for optoelectronics

Several optoelectronic applications require transparent and conductive "lms, usually deposited by RF- 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 cauli!ower-like structures. Such mesoporous electrodes exhibited enhanced electrochemical performances, compared to those of compact thin-"lm heterojunctions, due to the enhanced charge transfer at the ITO/TiO2 interface.