Ceramic SrTiO3 Photoanodes: Enhancement of Photoactivity Through Donor Doping
Abstract
Results are reported for the photoactivity of lanthanum-doped, strongly reduced SrTiO3 in microcrystalline ceramic form. Photoanodes of La(x)Sr(1-x)TiO3 (with x up to 0.01) were used in photoelectrochemical cells with simulated AM2 solar illumination, and aqueous electrolytes of various pH. The photoresponse was highest for strongly basic electrolytes, and 1M NaOH was used for subsequent experiments. Samples with heavy doping and strong reduction (heated at 1325 K with P(O2) equal to or less than 10 to the-18th atm, and quenched) showed good photoactivity without external bias. Impurity band formation for x equal to or greater than 0.003 provides an extension of the spectral response to longer wavelengths, and improves the quantum efficiency. Weakly doped samples (x equal to or less than 0.002) show a modest photo-oxidation after operation in a PEC cell for several hours, but this feature is absent for larger doping. No significant photodecomposition effects were seen after operation at AM2 illumination for up to 50 hr.
- Publication:
-
Journal of the Electrochemical Society
- Pub Date:
- February 1983
- DOI:
- 10.1149/1.2119703
- Bibcode:
- 1983JElS..130..321O
- Keywords:
-
- Ceramics;
- Doped Crystals;
- Photoelectrochemical Devices;
- Semiconductors (Materials);
- Spectral Sensitivity;
- Strontium Titanates;
- Anodes;
- Donor Materials;
- Lanthanum;
- Photodissociation;
- Energy Production and Conversion