Optoelectronic switches based on wide band gap semiconductors.
Switching of photocurrent direction in semiconducting systems upon changes of the electrode potential or incident light wavelength was realized by a series of photoelectrodes covered with titania modified with pentacyanoferrate complexes, [Fe(CN)(5)L](n)(-) (L = NH(3), thiodiethanol, thiodipropanol). These materials were characterized by optical spectroscopy and electrochemistry. The structure of the surface complexes was modeled using simple quantum-chemical models. The electrodes described in this paper enable control of the photocurrent direction by two stimuli: Changing the wavelength or the photoelectrode potential easily switches the direction of photocurrent. The materials are different from those of similar characteristics studied by other authors: They are not composites comprising of two types of semiconductors but rather engineered uniform materials. The photocurrent switching phenomenon is an intrinsic feature resulting from a specific electronic structure of the surface-modified semiconductor.
Hebda
Maciej
M
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
Stochel
Grazyna
G
Szaciłowski
Konrad
K
Macyk
Wojciech
W
D000641:Ammonia / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D005290:Ferric Compounds / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D007700:Kinetics; D008024:Ligands; D008956:Models, Chemical; D055095:Optics and Photonics; D010084:Oxidation-Reduction; D010777:Photochemistry; D012666:Semiconductors; D013440:Sulfides / Q000737:chemistry; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
D019187:Cadmium Compounds; D005290:Ferric Compounds; D005296:Ferrous Compounds; D008024:Ligands; D013440:Sulfides; C121008:pentacyanoferrate (III); C034939:cadmium sulfide; C058614:pentacyanoferrate (II); C009495:titanium dioxide; D000641:Ammonia; D014025:Titanium