Dynamic Quenching of Porous Silicon Excited States

Ko, Minh C.; Meyer, Gerald J.

doi:10.1021/cm960247o

Cited by 20 publications

(24 citation statements)

References 25 publications

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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%

“…To complicate matters further, there is good evidence that a significant amount of energy exchange occurs between the quantum-confined structures in the porous Si matrix. [96][97][98][99] Various approaches to obtain meaningful lifetime data from porous Si have been attempted, including the use of a stretched exponential fit [93,100] and calculation of an ''effective t'' based on integration of the intensity versus time curve. [23,91] The data are usually self-consistent, and at least they allow relative rate comparisons to be made.…”

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%

See 2 more Smart Citations

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%

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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“…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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“…Heterojunction devices have drawn a great attention in recent years mainly due to their use in optoelectronic field [18]. The heterojunction detector is one of the most important junctions because of the wide available technique that can be used to fabricate it, beside the wide range of radiation that could be detected by using this device [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of (Au/n-Sn/Si/Si/Al) MIS Device for Optoelectronic Application

Muhsien

Salem

Agool

2013

International Journal of Optics

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SnO 2 thin films were prepared by using rapid thermal oxidation (RTO) of Sn at oxidation temperature 873 K and oxidation time 90 sec on semiconductor n-type and p-type silicon substrate. In order to characterize the prepared device, the electrical properties have been measured which revealed that the barrier height is greatly depended on interfacial layer thickness (SiO 2). The value of peak response (n-SnO 2 /SiO 2 /n-Si) device was 0.16 A/W which is greater than that of (n-SnO 2 /SiO 2 /p-Si) device whose value was 0.12 A/W, while the rise time was found to be shorter.

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Dynamic Quenching of Porous Silicon Excited States

Cited by 20 publications

References 25 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

Preparation and Characterization of (Au/n-Sn/Si/Si/Al) MIS Device for Optoelectronic Application

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