6533b873fe1ef96bd12d581c
RESEARCH PRODUCT
Optimization of anodizing process of tantalum for Ta2O5-based capacitors
Andrea ZafforaFrancesco Di QuartoMonica SantamariaFrancesco Di-francosubject
Materials scienceDifferential capacitanceBand gapAnodizingInorganic chemistryOxideTantalumSodium adipatechemistry.chemical_element02 engineering and technologyElectrolyte010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectrochemistry01 natural sciences0104 chemical scienceschemistry.chemical_compoundSettore ING-IND/23 - Chimica Fisica ApplicatachemistryAnodizing Band gap Capacitor Dielectric properties Organic ions TantalumElectrochemistryGeneral Materials ScienceElectrical and Electronic Engineering0210 nano-technologydescription
Anodic oxides were grown to 50 V on Ta in several organic ions containing anodizing baths. Their properties were compared with anodic Ta oxide film grown to the same formation voltage in 0.1 M NaOH. Anodizing process carried out in sodium citrate led to the growth of the anodic oxide with the best blocking properties whilst, when Ta is anodized in sodium adipate, a significant part of the circulated charge is wasted in side reactions, such as oxygen evolution. Photoelectrochemical measurements showed the presence of optical transitions at energy lower than the band gap for the anodic films grown in citrate and tartrate electrolytes, attributed to localized electronic states located close to the valence band mobility edge of the films generated by anions incorporation into the oxide. Differential capacitance measurements proved an increase by 17% in capacitance value for the oxide grown in citrate-containing solution with respect to that grown in NaOH electrolyte. A sketch of the energetic of the metal/oxide interface is provided.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-11-01 |