Photoassisted Deposition of Chalcogenide Semiconductors on the Titanium Dioxide Surface:  Mechanistic and Other Aspects

Somasundaram, Sashikala; Chenthamarakshan, C. R.; Tacconi, Norma R. de; Ming, Yu; Rajeshwar, Krishnan

doi:10.1021/cm049293b

Cited by 74 publications

(70 citation statements)

References 30 publications

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“…The opposite effect is observed in the case of cathodic polarization with potentials higher than the Fermi level of the p-type component (Figure 7.14c). Composite materials with reported photocurrent switching following the above mechanism include p-n bulk structures based on n-TiO 2 -N/p-CuI [129], n-BiVO 4 /p-Co 3 O 4 [130], n-BiVO 4 /p-CuO [130], n-TiO 2 /p-Se [131,132], and n-CdS/p-CdTe [133]. If the optical criterion fails, the selective photoexcitation of semiconducting components is no longer possible.…”

Section: Composite Semiconductor Materialsmentioning

confidence: 99%

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Gawęda

Kowalik²,

Kwolek³

et al. 2012

Molecular and Supramolecular Information Processing

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Section: Composite Semiconductor Materialsmentioning

confidence: 99%

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Gawęda

Kowalik²,

Kwolek³

et al. 2012

Molecular and Supramolecular Information Processing

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“…32,33 Alternative techniques to increase the photoresponse besides doping include the utilization of tunable narrow band gap semiconductor nanoparticles or quantum dots (QDs) such as CdS, CdSe, and CdTe to sensitize wide band gap semiconductors such as the metal oxides, for example, TiO 2 and ZnO. [34][35][36][37] QDs with their large extinction coefficient strongly absorb visible light, inject electrons into the conduction band of metal oxides, and thereby, contribute to increased solar energy conversion. Attachment of CdSe QDs to nanocrystalline TiO 2 has been shown to be successful with an immersion method using a bimolecular linker.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications

et al. 2008

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Nitrogen-doped titanium dioxide (TiO 2 /N) nanoparticle thin films have been produced by a sol-gel method with hexamethylenetetramine (HMT) as the dopant source. The synthesized TiO 2 /N thin films have been sensitized with CdSe quantum dots (QDs) via a linking molecule, thioglycolic acid (TGA). Optical, morphological, structural, and photocurrent properties of the thin films with and without QD sensitization have been characterized by AFM, TEM, XPS, Raman spectroscopy, UV-visible spectroscopy, and photoelectrochemistry techniques. AFM measurements reveals that films with thicknesses of 150 and 1100 nm can be readily prepared, with an average TiO 2 particle size of 100 nm. TEM shows a uniform size distribution of CdSe QDs utilized in sensitizing the TiO 2 /N films. Doping of the TiO 2 crystal lattice by HMT was confirmed to be 0.6-0.8% by XPS. Differences in crystal phase caused by the precursors HMT, nitric acid, and poly(ethylene glycol) (PEG) are elucidated using XRD and Raman spectroscopy. The resultant crystal phase of TiO 2 /N varies but is a mixture of anatase, brookite, and rutile phases. UV-visible absorption spectra show that N doping of TiO 2 causes a red-shifted absorption into the visible region, with an onset around 600 nm. Nitrogen doping is also responsible for the enhanced photocurrent response of the TiO 2 /N nanoparticle films in the visible region relative to undoped TiO 2 films. In addition, CdSe QDs linked to TiO 2 /N nanoparticles using TGA were found to significantly increase the photocurrent and power conversion of the films compared to standard TiO 2 /N films without QD sensitization. The incident photon-to-current conversion efficiency (IPCE) is 6% at 400 nm for TiO 2 /N-TGA-CdSe solid-state solar cells and 95% for TiO 2 /N-TGA-CdSe films near 300 nm in a Na 2 S electrolyte, which is much higher than that of undoped TiO 2 with QD sensitization or TiO 2 /N without QD sensitization. The power conversion efficiency (η) was found to be 0.84% with a fill factor (FF%) of 27.7% with 1100 nm thick TiO 2 /N-TGA-CdSe thin films. The results show that combining nitrogen doping with the QD sensitization of TiO 2 thin films is an effective and promising way to enhance the photoresponse in the near-UV and visible region, which is important for potential photovoltaic (PV) and photoelectrochemical applications.

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“…Thus, the photoreduction of selenite and selenate ions on the surface of the TiO 2 nanoparticles leads to the formation of TiO 2 /Se [97][98][99][100][101][102] nanostructures. Realization of this reaction in the presence of Cd II and Pb II makes it possible to produce TiO 2 /CdSe [103] and TiO 2 /PbSe [100,101] nanostructures respectively.…”

Section: Photocatalytic Synthesis Of Selenium-containing Nanoheterostmentioning

confidence: 99%

Photochemical formation of semiconducting nanostructures

et al. 2008

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Existing data on photochemical and photocatalytic approaches to the formation of semiconducting nanoparticles and also binary semiconducting nanostructures and nanocomposites of semiconductors with metals and polymers are reviewed. The nature of the effect of irradiation on the synthesis and properties of the obtained nanostructures and the possibility of photocatalytic control of the structural and spectral parameters of nanostructural semiconducting systems are examined.The accumulation of data on the properties of semiconducting (SC) nanomaterials, which has occurred particularly rapidly in the last 7-10 years, has opened up ever more alluring prospects for their application as light-sensitive and light-emitting components in nanophotonics [1-3], nanophotocatalysis [2,[4][5][6][7], biosensorics [8][9][10][11], and other important fields. The possibility of practical utilization is an important factor that has stimulated the search for and study of the processes involved in the formation of nanomaterials. On this account an enormous number of publications have now accumulated on the improvement of existing and development of new methods for the synthesis of semiconducting nanoparticles and nanostructures (e.g., see the reviews [6, 12-15]). A special position among them is occupied by methods based on photochemical transformations conducted either for the purpose of synthesis and directing it along a desired path or for improving the characteristics of nanostructures produced by other methods.Photochemical methods of synthesis have proved more effective than the production of nanomaterials by traditional synthetic approaches, and in a number of cases only they make it possible to achieve the assigned aim. For this reason the synthesis of semiconducting nanostructures and their modification under the conditions of photoirradiation are constantly attracting the attention of investigators, and the number of publications devoted to these questions is constantly increasing. We note, however, that they nevertheless remain disjointed.In view of the foregoing an attempt is made in the present article to organize existing data, to identify the most important directions for research and development, and thus to assess the current state of development of photochemical approaches to the formation of semiconducting nanostructures. Analysis of data on the photochemical formation and post-synthesis photochemical treatment of semiconducting nanostructures and multicomponent nanocomposites, including the nanoparticles of metals and polymers in addition to semiconductors, showed that in spite of the variety and diversity of the proposed approaches all the papers can be ascribed to only three courses: synthesis, synthesis control, and changing the characteristics of the semiconducting nanostructures. For this reason in this review photochemical approaches to the synthesis of nanoparticles of metal chalcogenides, binary semiconducting nanostructures, and nanocomposites consisting of semiconducting and conducting polymers are examin...

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Photoassisted Deposition of Chalcogenide Semiconductors on the Titanium Dioxide Surface: Mechanistic and Other Aspects

Cited by 74 publications

References 30 publications

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications

Photochemical formation of semiconducting nanostructures

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Photoassisted Deposition of Chalcogenide Semiconductors on the Titanium Dioxide Surface: Mechanistic and Other Aspects

Cited by 74 publications

References 30 publications

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Hybrid Semiconducting Materials: New Perspectives for Molecular‐Scale Information Processing

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO2 Films for Solar Energy Conversion Applications

Photochemical formation of semiconducting nanostructures

Contact Info

Product

Resources

About

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications