Patterning porous matrices and planar substrates with quantum dots

Bertino, Massimo F.; Gadipalli, R. R.; Martin, Lane; Story, J. G.; Heckman, B.; Guha, S.; Leventis, Nicholas

doi:10.1007/s10971-006-8165-5

Cited by 12 publications

(7 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All these techniques showed that the nanoparticles were free of contamination, and that they had a bulk crystalline structure. In this work, we characterized the nanoparticles using Raman spectroscopy, and the results were in agreement with our previous research [15][16][17]. Representative Raman spectra are shown in figure 4 for CdS and PbS patterns obtained with x-ray lithography.…”

Section: Materials Characterizationsupporting

confidence: 88%

“…In samples containing the same precursor concentration, clearly visible patterns were formed five to ten times more rapidly when selenourea was used instead of the 2-mercaptoethanol (RSH) used previously. In addition, the molar absorptivity at 254 nm (Hg line) of the Cd 2+ -RSH precursor combination is 3.2 × 10 4 M −1 cm −1 [17]; the molar absorptivity of Cd 2+selenourea is 1.0 × 10 4 M −1 cm −1 . When the differences in absorptivities and exposure times are taken into account, we obtain that UV irradiation of Cd 2+ -selenourea is 15-30 times more efficient than that of Cd 2+ -RSH.…”

Section: Photodissociation and Reaction Mechanismsmentioning

confidence: 97%

“…Only relatively primitive patterns could be produced by translating the sample in front of the focused beam. We then showed that ultraviolet light (UV) can also be employed to pattern substrates with quantum dots [17]. However, photodissociation of the thiol precursors employed in the UV experiments was not very efficient.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Quantum dots by ultraviolet and x-ray lithography

et al. 2007

View full text Add to dashboard Cite

Highly luminescent semiconductor quantum dots have been synthesized in porous materials with ultraviolet and x-ray lithography. For this, the pore-filling solvent of silica hydrogels is exchanged with an aqueous solution of a group II metal ion together with a chalcogenide precursor such as 2-mercaptoethanol, thioacetamide or selenourea. The chalcogenide precursor is photodissociated in the exposed regions, yielding metal chalcogenide nanoparticles. Patterns are obtained by using masks appropriate to the type of radiation employed. The mean size of the quantum dots is controlled by adding capping agents such as citrate or thioglycerol to the precursor solution, and the quantum yield of the composites can be increased to up to about 30% by photoactivation. Our technique is water-based, uses readily available reagents, and highly luminescent patterned composites are obtained in a few simple processing steps. Polydispersity, however, is high (around 50%), preventing large-scale usage of the technique for the time being. Future developments that aim at a reduction of the polydispersity are presented.

show abstract

Section: Materials Characterizationsupporting

confidence: 88%

Section: Photodissociation and Reaction Mechanismsmentioning

confidence: 97%

See 1 more Smart Citation

Quantum dots by ultraviolet and x-ray lithography

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Also by functionalizing the nanocrystals surfaces with either hydrophobic or hydrophilic ligands, as discussed previously, they can bind to selected sites on the substrate forming dual color arrays [163]. More recently, using the sol-gel technique, QDs patterns were formed by using UV assisted photosynthesis [164]. Using this method a precursor solution was spin coated on a subtract and illuminated by a patterned UV beam.…”

Section: Optical Fiber Sensingmentioning

confidence: 99%

Optical Fiber Sensing Using Quantum Dots

Jorge

Martins

Trindade

et al. 2007

Sensors

114

View full text Add to dashboard Cite

Recent advances in the application of semiconductor nanocrystals, or quantum dots, as biochemical sensors are reviewed. Quantum dots have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based bioanalytical techniques. An overview of the more relevant progresses in the application of quantum dots as biochemical probes is addressed. Special focus will be given to configurations where the sensing dots are incorporated in solid membranes and immobilized in optical fibers or planar waveguide platforms.

show abstract

“…However, progress in this direction has been sluggish. Very recently, patterning of substrates with quantum dots was reported, and it was obtained with a bottom-up approach [21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%