Photosensitization of thin SnO2 nanocrystalline semiconductor film electrodes with metalloporphyrins and alkyl‐substituted metalloporphyrins

Photosensitization of Thin SnO2Nanocrystalline Semiconductor Film Electrodes with Metallodiporphyrin

“…In the presence of H 2 Q, a higher stationary anodic photocurrent is observed during illumination and the cathodic current is suppressed. This observation is in agreement with other dye-sensitized oxide electrodes . Similar results were obtained with the P Zn and P Zn − P dyad.…”

Photosensitization of Thin SnO2Nanocrystalline Semiconductor Film Electrodes with Metallodiporphyrin

“…In the presence of H 2 Q, a higher stationary anodic photocurrent is observed during illumination and the cathodic current is suppressed. This observation is in agreement with other dye-sensitized oxide electrodes . Similar results were obtained with the P Zn and P Zn − P dyad.…”

Photoelectrochemistry of a Substituted-Ru(bpy)32+-Labeled Polyimide and Nanocrystalline SnO2 Composite Formulated as a Thin-Film Electrode

“…A transparent thin-film electrode I fashioned from sequentially deposited layers of nanocrystalline SnO 2 exhibits photoelectrochemical characteristics similar to those described by Kamat . The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 μm . This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 μm.…”

“…13 The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 µm. 26 This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 µm. Although more photons are harvested by a thicker dye-coated SnO 2 film (because of higher loading of the sensitizer), there is a higher probability of recombination of the photogenerated electrons and holes when these carriers must partake of a large number of random hops as they migrate through the thicker film because of the larger number of colloidal particles and grain boundaries encountered.…”

Synthesis of porphyrin dyads with potential use in solar energy conversion

“…This fact con®rms that light absorption by the porphyrin dyads is the initial step in the generation of photo-induced charge transfer mechanism, like in the natural photosynthetic apparatus. 6…”

Photosensitization of Thin SnO2Nanocrystalline Semiconductor Film Electrodes with Metallodiporphyrin

“…In the presence of H 2 Q, a higher stationary anodic photocurrent is observed during illumination and the cathodic current is suppressed. This observation is in agreement with other dye-sensitized oxide electrodes . Similar results were obtained with the P Zn and P Zn − P dyad.…”

Photoelectrochemistry of a Substituted-Ru(bpy)32+-Labeled Polyimide and Nanocrystalline SnO2 Composite Formulated as a Thin-Film Electrode

“…A transparent thin-film electrode I fashioned from sequentially deposited layers of nanocrystalline SnO 2 exhibits photoelectrochemical characteristics similar to those described by Kamat . The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 μm . This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 μm.…”

“…13 The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 µm. 26 This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 µm. Although more photons are harvested by a thicker dye-coated SnO 2 film (because of higher loading of the sensitizer), there is a higher probability of recombination of the photogenerated electrons and holes when these carriers must partake of a large number of random hops as they migrate through the thicker film because of the larger number of colloidal particles and grain boundaries encountered.…”

Synthesis of porphyrin dyads with potential use in solar energy conversion

“…This fact con®rms that light absorption by the porphyrin dyads is the initial step in the generation of photo-induced charge transfer mechanism, like in the natural photosynthetic apparatus. 6…”

Photosensitization of Thin SnO2Nanocrystalline Semiconductor Film Electrodes with Metallodiporphyrin

“…In the presence of H 2 Q, a higher stationary anodic photocurrent is observed during illumination and the cathodic current is suppressed. This observation is in agreement with other dye-sensitized oxide electrodes . Similar results were obtained with the P Zn and P Zn − P dyad.…”

Photoelectrochemistry of a Substituted-Ru(bpy)32+-Labeled Polyimide and Nanocrystalline SnO2 Composite Formulated as a Thin-Film Electrode

“…A transparent thin-film electrode I fashioned from sequentially deposited layers of nanocrystalline SnO 2 exhibits photoelectrochemical characteristics similar to those described by Kamat . The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 μm . This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 μm.…”

“…13 The magnitude of the photocurrent produced by photosensitization by zinc porphyrin adsorbed onto an analogous nanocrystalline SnO 2 thin film has been shown to increase linearly with film thickness for very thin films but to level off at thicknesses >0.25 µm. 26 This observation indicates that nanocrystalline SnO 2 thin films such as I are highly porous and that the net efficiency of electron hopping among the constituent SnO 2 nanoparticles before reaching the ITO conductive support reaches a maximum at a SnO 2 thickness of about 0.25 µm. Although more photons are harvested by a thicker dye-coated SnO 2 film (because of higher loading of the sensitizer), there is a higher probability of recombination of the photogenerated electrons and holes when these carriers must partake of a large number of random hops as they migrate through the thicker film because of the larger number of colloidal particles and grain boundaries encountered.…”

Synthesis of porphyrin dyads with potential use in solar energy conversion

“…This fact con®rms that light absorption by the porphyrin dyads is the initial step in the generation of photo-induced charge transfer mechanism, like in the natural photosynthetic apparatus. 6…”