Photoluminesce quenching

Matsumoto, Y, Kanemoto, R Itoh, T, Nakanishi, S Ishikawa, M. and Biju, V. (2008) Photoluminescence quenching and intensity fluctuations of CdSe-ZnS quantum dots on an Ag nanopartide film. /. Phys. Chem. C, 112, 1345-1350. 

VE Choong, Y Park, N Shivaparan, CW Tang, and Y Gao, Deposition-induced photoluminescence quenching of tris-(8-hydroxyquinoline) aluminum, Appl. Phys. Lett., 71 1005-1007, 1997. 

Sodium hexametaphosphate AOT isooctane H20 reversed micelles CdS Photoluminescence quenching of thiophenol-capped, sizequantized CdS (by KI and methylviologen) is examined 98... 

The crystalline composites obtained between poly(3-alkylthiophene) and polystyrene showed an enhanced conductivity (07MM6579). The preparation of regioregular poly(3-alkylthiophene) and perylene diimide derivatives composites have been reported (06MI384). The photoluminescence spectra of this type of composites exhibit a significant photoluminescence quenching of the perylene diimide derivative. This result implies that the light absorbed by the perylene diimide units could also contribute to the generation of current at the photovoltaic device. 

Studies on luminescence of CdS colloids provide useful knowledge on the energy and nature of recombination sites of charge carriers in the colloidal particles. The regularities of the colloid photoluminescence quenching provide the information on the dynamics of electrons and holes in semiconductor particles as well as on the kinetics of interfacial electron transfer. Of a particular interest are studies on the luminescence of colloidal solutions of the so-called Q-semiconductors, their properties depending on the size of semiconductor particles due to the quantum size effects. 

Such bilayers were studied by photoluminescence, with a view to extracting the degree of photoluminescence quenching induced by a thin acceptor layer on the polymer [18]. Studies of photoluminescence quenching in bilayers have corroborated the picture derived from studies of photoelectrical performance. The short exciton diffusion length in PEOPT is 5 nm, consistent with both PL quenching and photodiode performance. 

Figure 13 The field dependence of the photogeneration efficiency of a dual-layer photoreceptor, a single-layer photoreceptor, and the photoluminescence quenching of the dual-layer photoreceptor. The generation layer contained AZO-FO. The transport layer contained a stilbene derivative (MAPS).

Table 1. Photoluminescence quenching and steady-state photoelectrochemcial data for Ru(tap)3 +-H2Q systems.

The photoconductivity (AIp /Ip, ) and the photoluminescence quenching ( - AIl(E)/Il) obtained at 77 K are plotted versus the bias field in Fig. VD-1. The data indicate clearly that the onset field for the nonlinear photocurrent, EP " = 0.77 X 10 V/cm, is lower by about 50% than the onset field of the luminescence quenching, EP =1.7x 10 V/cm. Below E5 the photocurrent is linearly dependent on E, and below E, the luminescence is field independent. At the highest electric fields employed in the transient photoconductivity experiment (E = 2.8x10 V/cm), - AIl(E)/Il 0.30, whereas the photocurrent increases beyond the linear extrapolation by a factor of = 6.3. 

Earlier measurements of photoluminescence quenching in PPV derivatives yielded E ] = 2xl0 V/cm [165], an order of magnitude larger than E as... 

The photoluminescence quenching of semiconductor CdSe/ZnS quantum dots (QDs) caused by suifacely attached porphyrins increases with QDs size decrease. Porphyrin-QD interaction induces a pertubation of the excitonic wave function leading to a net charge localisation of the electron-hole pair accompanied by an increase of radiationless decay rates being proportional to the calculated radial probability of the confined exciton wave function at QD surface. 

Brus, L. Model for carrier dynamics and photoluminescence quenching in wet and dry porous silicon thin films. Phys. Rev. B 1996, 53, 4649-4656. 

GreenhamN. C, Peng X. and Alivisatos A. P. (1996), Charge separation and transport in conjugated-polymer/semicondnctor-nanocrystal composites studied by photoluminescence quenching andphotocondnctivity , Phys. Rev. B 54, 17628-17637. 

Snaith et al. investigated F8BT PFB blends with respect to the blending ratio [237]. They found that the photoluminescence quenching efficiency was rather insensitive to the blending ratio, whereas the highest EQEs were... 

The authors showed by applying the Onsager model to electric field-dependent photoluminescence quenching data [49,247,248] that the gemi-... 

Fig. 2.39 Photoluminescence quenching spectra for 5 (red continuous curve), 10 (green curve), and 20 mW (blue curve) excitation power normalized to the corresponding excitation power as well as photoluminescence quenching versus modulation frequency...

In the absence of the exciton energy diffusion within the intrinsic EDOS distribution, i. e. with q = 0, Eq. (3.15) reduces to the (t/r)1/2 dependence obtained by Klafter and Blumen [84] for the Forster-type donor photoluminescence quenching by randomly distributed exciton acceptors. 

Photoluminescence quenching may arise from either a static process, by the quenching of a bound complex, or a dynamic process, by collisionally quenching the excited state [47,48]. For the former mechanistic case, Ksg represents an association constant for analyte binding to the polymer chain in... 

For chemosensor electronic nose applications, it is useful to have sensors with varied responses. The 12 different luminescent polymers (9-12 are germole copolymers) examined [41] exhibit a different ratio of the photoluminescence quenching for picric acid, TNT, DNT, and nitrobenzene and a different response with the same analyte, as shown in Figure 8. 

Fig. 9. Dependence of the Urbach slope parameter Eo (left scale) and photoluminescence quenching parameter To (right scale) on a-Si H layer thickness Lg. [From Abeles and Tiedje...

The reactivity of the photoexcited Cr oxide species with reactant gasses (H2 and CO) was investigated by photoluminescence quenching measurements. The... 

Based on the comparisons of (1) photoluminescence quenching in bipolar and holes-only devices and (2) photo- and electroluminescence loss in bipolar devices, the plausible hypo esis was put forward that the instability of Alq cation-radicals plays a key role in bipolar devices as well as in holes-only devices [62]. However, considering that the concentrations of Alq cation-radicals could be substantially less in operating bipolar devices relative to holes-only devices, the alternative degradation mechanisms, involving, for example, unimolecular reactions of excited states or bimolecular reactions of charge carriers and excited states, cannot be rigorously ruled out. 

Key words porous silicon, gas sensor, photoluminescence quenching, noise. 

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