Dynamic Quenching of Porous Silicon Photoluminescence by Anthracene and 10-Methylphenothiazine

Ko, Minh C.; Meyer, Gerald J.

doi:10.1021/cm00049a004

Cited by 34 publications

(44 citation statements)

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“…[23,24,[88][89][90][91][92][93][94] Typically, the experiments are performed by titration of the porous Si sample with a nonaqueous solution containing the quencher molecule of interest. Figure 4 shows the photoluminescence spectra observed during the course of a titration with 9,10-diphenylanthracene.…”

Section: Quenching Mechanisms: Charge and Energy Transfermentioning

confidence: 99%

“…[101] Our experiments, and those of McLendon, Fauchet, Meyer, and others have provided a fairly complete picture of the excited state energetics of porous Si. [92,93,99,101,102] An interesting medical application involving the energy transfer quenching mechanism has been proposed by Fujii, Kovalev, and co-workers. We first observed and quantified the efficient quenching of porous Si photoluminescence by oxygen in 1997.…”

Section: Quenching Mechanisms: Charge and Energy Transfermentioning

confidence: 99%

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Photoluminescence‐Based Sensing With Porous Silicon Films, Microparticles, and Nanoparticles

Sailor

2009

Adv Funct Materials

150

107

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Here, chemical sensors made from porous Si are reviewed, with an emphasis on systems that harness photoluminescence and related energy‐ and charge‐transfer mechanisms available to porous Si‐derived nanocrystallites. Quenching of luminescence by molecular adsorbates involves the harvesting of energy from a delocalized nanostructure that can be much larger than the molecule being sensed, providing a means to amplify the sensory event. The interaction of chemical species on the surface of porous Si can exert a pronounced influence on this process, and examples of some of the key chemical reactions that modify either the surface or the bulk properties of porous Si are presented. Sensors based on micron‐scale and smaller porous Si particles are also discussed. Miniaturization to this size regime enables new applications, including imaging of cancerous tissues, indirect detection of reactive oxygen species (ROS), and controlled drug release. Examples of environmental and in vivo sensing systems enabled by porous Si are provided.

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Section: Quenching Mechanisms: Charge and Energy Transfermentioning

confidence: 99%

Section: Quenching Mechanisms: Charge and Energy Transfermentioning

confidence: 99%

Photoluminescence‐Based Sensing With Porous Silicon Films, Microparticles, and Nanoparticles

Sailor

2009

Adv Funct Materials

150

107

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“…Other studies have reported the PL quenching from p-Si by metal ions in solutions of Cu 2+ , Ag + , and Au 3+ ; 23,24 surfactants; 25 and polycyclic organic and dye molecules. [26][27][28] In relation to the quenching studies, reduction of the PL intensity from p-Si upon exposure to methanol and quenching of the H-terminated p-Si have been reported. 29,30 Brus applied an electron-kinetics model to study the PL in wet and dry p-Si.…”

Section: Introductionmentioning

confidence: 99%

Decay Dynamics and Quenching of Photoluminescence from Silicon Nanocrystals by Aromatic Nitro Compounds

Germanenko

El‐Shall

2000

J. Phys. Chem. B

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The decay dynamics and the quenching of the photoluminescence (PL) from Si nanocrystals are investigated. Electron acceptors whose reduction potentials lie below the conduction band (CB) edge of the Si nanocrystals quench the red emission from the Si nanocrystals. The quenching rate constants obtained from Stern-Volmer analyses for 3,5-dinitrobenzonitrile, 4-nitrophthalonitrile, 1,4-dinitrobenzene, 4-nitrobenzonitrile, 2,3-dinitrotoluene, 3,4-dinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene are in the range of 10 6 -10 7 M -1 s -1 . The quenching mechanism occurs via an electron transfer from the CB band of the Si nanocrystals to the vacant orbitals of the quenchers. The PL decay profiles of the Si nanocrystals, in the presence and absence of the quencher, are well described by the stretched exponential decay law. The band gap of the Si nanocrystals estimated from the present study is larger than the PL peak energy. The results are consistent with a quantumconfinement model, where recombination of electrons and holes occurs in a surface state. The ability of nitrotoluenes to quench the PL from Si nanocrystals could be used to develop a sensor based on Si nanostructures for the detection of explosives. IntroductionSilicon nanostructures have stimulated much interest because of their unique properties such as single-electron tunneling, nonlinear optical properties, and visible photoluminescence (PL). 1-7 Studies of Si nanostructures have grown extensively since the discovery of efficient PL from porous Si (p-Si) with the ultimate goals of achieving a complete fundamental understanding of the phenomenon as well as developing potential display devices and chemical-sensor applications. 1-10 Si nanocrystals have optical and PL properties very similar to those of p-Si, and it is generally accepted that they are the emitting chromophores in p-Si. Kinetic quantum confinement appears to be the most reliable model to explain the origin and properties of the PL from Si nanocrystals. The higher energy shift in the PL of Si nanocrystals is attributed to the three-dimensional quantum size effect. The nonradiative recombination process is decreased significantly in the nanocrystal as the electronhole pairs in separate nanocrystals are electrically isolated. However, in both p-Si and Si nanocrystals, the PL properties are related not only to the respective nanocrystalline size but also to the structure and properties of the surrounding medium. The study of these effects is essential for utilizing Si nanostructures in potential device applications.Many organic and inorganic molecules have been shown to efficiently quench the PL from p-Si, and both energy-and electron-transfer mechanisms have been proposed to explain this PL quenching. 11-30 Sailor and co-workers found a number of polar solvent molecules that reversibly quenched the PL from p-Si. 11-15 They also studied the quenching by aromatic molecules and concluded that energy transfer from the p-Si excited state to the triplet levels of the quencher molecules predomi...

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“…Possible mechanisms for this quenching have been proposed elsewhere. [3][4][5][6][7][8][9][10][11] Once a light oxide has formed, solvents cease to have a general quenching effect, but strong PL quenching by bases is still observable. With the formation of an oxide, acidic protons become available for abstraction.…”

Section: Resultsmentioning

confidence: 99%

General Brönsted Acid Behavior of Porous Silicon: A Mechanistic Evaluation of Proton-Gated Quenching of Photoemission from Oxide-Coated Porous Silicon

1997

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Photoinduced visible light emission from porous silicon can be reversibly quenched by a wide variety of chemical species. The growth of a thin layer of oxide on the porous silicon surface disrupts the quenching ability of most species, narrowing down the number of quenchers to include primarily those which act as Brönsted bases. Electron paramagnetic resonance spectroscopy, infrared spectroscopy, photoluminescence data, and surface chemistry suggest a quenching mechanism which involves the extraction of a nonspecifically attached proton in the oxide layer upon exposure to base. This proton is loosely affiliated with a surface defect of the P b type. This defect serves as a hole trap in the absence of a proton providing a nonradiative relaxation pathway. However, when a proton is present in the oxide layer, Coulombic interactions force the hole trap into a state which falls below the bandgap, allowing for efficient radiative recombination of electronhole pairs. The electron paramagnetic resonance spectroscopy data also demonstrate that there are at least two distinct mechanisms of luminescence quenching of porous silicon.

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Dynamic Quenching of Porous Silicon Photoluminescence by Anthracene and 10-Methylphenothiazine

Cited by 34 publications

References 0 publications

Photoluminescence‐Based Sensing With Porous Silicon Films, Microparticles, and Nanoparticles

Photoluminescence‐Based Sensing With Porous Silicon Films, Microparticles, and Nanoparticles

Decay Dynamics and Quenching of Photoluminescence from Silicon Nanocrystals by Aromatic Nitro Compounds

General Brönsted Acid Behavior of Porous Silicon: A Mechanistic Evaluation of Proton-Gated Quenching of Photoemission from Oxide-Coated Porous Silicon

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