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RESEARCH PRODUCT
Photoelectrochemical study on anodic aluminum oxide films. Internal photoemission processes at the metal-oxide interface
Carmelo SunseriF. Di QuartoSalvatore PiazzaC. Gentilesubject
PhotocurrentAluminium oxidesMaterials scienceRenewable Energy Sustainability and the Environmentbusiness.industryBand gapInorganic chemistryOxideElectronElectrolyteCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsAnodechemistry.chemical_compoundchemistryElectric fieldMaterials ChemistryElectrochemistryOptoelectronicsbusinessdescription
A photoelectrochemical investigation has been carried out on aluminum oxide films grown anodically at constant rate up to different thicknesses. Depending on the potential both anodic and cathodic photocurrents were observed at photon energies well below the optical bandgap expected for these layers. This finding is explained with the presence of internal photoinjection processes both for electrons and holes from the base metal into the oxide film. The analysis of the photocurrent spectra has given the threshold energies for both processes. The effect of the image force at the metal/oxide interface has been taken into account in order to derive the mobility gap of the films and the energetics of the overall junction. Interference phenomena were observed on the anodic photocurrent recorded during the growth of the films. These effects have been utilized to get an estimate of the electric field within the film during the growth. Trapping phenomena for both photoinjected carriers are postulated to explain the experimental results, according to recent theoretical considerations on the metal/oxide/electrolyte systems.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1991-06-01 |