Modulation of the time-resolved photoluminescence of cadmium selenide by adduct formation with gaseous amines

Leung, Larry K.; Meyer, Gerald J.; Lisensky, George C.; Ellis, Arthur B.

doi:10.1021/j100367a004

Cited by 7 publications

(11 citation statements)

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“…In addition, time-resolved PL data demonstrated that the PL decay traces obtained in nitrogen and in the presence of ammonia for the etched sample were indistinguishable, supporting the notion that the PL changes found in the continuous excitation experiments are driven principally by electric field changes rather than by changes in surface recombination velocity (8). This observation is consistent with reduction in the acidity of the borane by replacement of a halide substituent with an electron-donating alkyl substituent.…”

Section: Symposium: Applications Of Inorganic Photochemistrysupporting

confidence: 67%

“…For ammonia and the boranes, a good fit to the dead-layer model was obtained for etched CdSe substrates. In addition, time-resolved PL data demonstrated that the PL decay traces obtained in nitrogen and in the presence of ammonia for the etched sample were indistinguishable, supporting the notion that the PL changes found in the continuous excitation experiments are driven principally by electric field changes rather than by changes in surface recombination velocity (8). The specific separation of these two factorschanges in electric field and surface recombination-is difficult in practice from transient PL measurements, since both factors depend on the relative magnitudes of the carrier lifetimes in the bulk and at the surface.…”

Section: Symposium: Applications Of Inorganic Photochemistrymentioning

confidence: 52%

“…Most of the experiments described in this article are conducted with continuous excitation. Time-resolved experiments, however, afford the opportunity to monitor the decay of the excess electron-hole pairs in real time (8)(9)(10). A figure of merit in evaluating interfaces derived from semiconductors is the surface recombination velocity, S. This parameter has velocity units, typically cm/s, and reflects the rate at which minority carriers (holes in n-type materials) are consumed at the surface of the semiconductor.…”

Section: Modulation Of the Photoluminescence Of Semiconductors By Sur...mentioning

confidence: 99%

“…Time-resolved experiments, however, afford the opportunity to monitor the decay of the excess electron-hole pairs in real time (8)(9)(10). Most of the experiments described in this article are conducted with continuous excitation.…”

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confidence: 99%

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Modulation of the Photoluminescence of Semiconductors by Surface Adduct Formation: An Application of Inorganic Photochemsitry to Chemical Sensing

et al. 1997

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Semiconductors provide a unique perspective on inorganic photochemistry. The electronic structure of common semiconductors permits a coupling of optical and electrical phenomena (1). As a consequence, semiconductors have found widespread use in many common electrooptical devices, including light-emitting diodes (LEDs), diode lasers, and solar cells. In the case of LEDs and diode lasers, electrical excitation produces a highly emissive excited state of the solid; in contrast, in solar cells, photoexcitation can produce an electrical output.Interfaces derived from semiconducting solids afford opportunities for chemical control of their electro-optical properties. The intent of this article is to describe the construction and operation of chemical sensors based on the photoluminescence (PL) of semiconducting solids. We and others have shown that adduct formation involving the binding of ambient molecules to the semiconductor surface can lead to reversible PL changes that can be used as the basis for on-line sensor structures (2, 3). Because these devices link surface coordination chemistry to the electrical and excited-state properties of the semiconductor substrates, they provide a rich collection of applications of inorganic photochemistry. Physical and Electronic StructureOf the common inorganic semiconductors, the emissive II-VI compounds CdS and CdSe [CdS(e)] have proven to be particularly versatile sensor substrates. These solids have the wurtzite crystal structure, illustrated in Figure 1, which comprises hexagonal closepacked chalcogen atoms with half of the tetrahedral holes filled by cadmium atoms (4). Thus, each type of atom is tetrahedrally coordinated exclusively by atoms of the other type. Figure 1 also reveals the polar nature of the CdS(e) crystal: the (0001) face at the top of the figure consists exclusively of Cd atoms, and the opposing (0001) face exclusively of chalcogen atoms (5). Most studies of adduct formation onto single-crystal CdS(e) samples have employed the more highly emissive (0001) face, which is more accurately described as a Cd-rich

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Section: Symposium: Applications Of Inorganic Photochemistrysupporting

confidence: 67%

Section: Symposium: Applications Of Inorganic Photochemistrymentioning

confidence: 52%

Section: Modulation Of the Photoluminescence Of Semiconductors By Sur...mentioning

confidence: 99%

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confidence: 99%

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Modulation of the Photoluminescence of Semiconductors by Surface Adduct Formation: An Application of Inorganic Photochemsitry to Chemical Sensing

et al. 1997

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“…Fluorescence decay times were determined by means of a Hamamatsu C4334 streak camera system. Samples were excited by 355 nm, 3.5 pJ, 500 ps laser pulses at 5 kHz, generated by a Quantronix 4000 Nd:YAG (Q-switched, mode-locked, pulse-picked, and frequency-tripled by a BBO crystal), and the decay data were fed into a personal computer and fitted to the two-parameter Kohlraush equation: where I 0 is the fluorescence intensity at t = 0 and the parameter β (0 < β < 1) is related to a distribution of decay times that are serially linked to the lifetime (τ), which represents the peak of distribution.…”

Section: Methodsmentioning

confidence: 99%

Coupled Composite CdS−CdSe and Core−Shell Types of (CdS)CdSe and (CdSe)CdS Nanoparticles

et al. 1996

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Addition of H2S and H2Se, in different proportions, to aqueous Cd(ClO4)2 solutions containing (NaPO3)6 led to the formation of coupled composite CdS−CdSe nanoparticles. Conversely, the sequential introduction of different amounts of H2S and H2Se (or H2Se and H2S) into aqueous Cd(ClO4)2 solutions containing (NaPO3)6 produced core−shell type (CdS)CdSe [or (CdSe)CdS] nanoparticles. These structural assignments were based on spectroscopic (absorption, transmission, excitation, and emission), electrochemical, pulse radiolytic, and electron microscopic measurements. Conditions were adjusted (by adding excess cadmium and hydroxide ions) for the maximization of excitonic fluorescence. Two emission bands were observed in the coupled and in the core−shell type mixed semiconductor nanoparticles. The first one, centered around 470 nm, was attributed to the 1se−1sh excitonic emission of CdS. The second, centered around 560 nm, was proposed to arise from charge transfer of CdS to the coupled composite CdS−CdSe and core−shell type (CdS)CdSe [or (CdSe)CdS] nanoparticles.

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Photoluminescence of Inorganic Semiconductors for Chemical Sensor Applications

Meyer

1999

Optoelectronic Properties of Inorganic Compounds

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Modulation of the time-resolved photoluminescence of cadmium selenide by adduct formation with gaseous amines

Cited by 7 publications

References 0 publications

Modulation of the Photoluminescence of Semiconductors by Surface Adduct Formation: An Application of Inorganic Photochemsitry to Chemical Sensing

Modulation of the Photoluminescence of Semiconductors by Surface Adduct Formation: An Application of Inorganic Photochemsitry to Chemical Sensing

Coupled Composite CdS−CdSe and Core−Shell Types of (CdS)CdSe and (CdSe)CdS Nanoparticles

Photoluminescence of Inorganic Semiconductors for Chemical Sensor Applications

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