LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 3 of total 3

Search options

  1. Article ; Online: Structure and dynamics of triplet-exciton pairs generated from singlet fission studied via magnetic field effects

    Masanobu Wakasa / Tomoaki Yago / Yoriko Sonoda / Ryuzi Katoh

    Communications Chemistry, Vol 1, Iss 1, Pp 1-

    2018  Volume 6

    Abstract: Singlet fission events could be exploited to improve solar cell performance, but currently their characterization is challenging. Here, the authors exploit magnetic field effects at low magnetic field strengths to determine the structure and diffusion ... ...

    Abstract Singlet fission events could be exploited to improve solar cell performance, but currently their characterization is challenging. Here, the authors exploit magnetic field effects at low magnetic field strengths to determine the structure and diffusion pathways of triplet-exciton pairs and to predict the efficiency of singlet fission events.
    Keywords Chemistry ; QD1-999
    Language English
    Publishing date 2018-03-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article: Diffusion-Mediated Delayed Fluorescence by Singlet Fission and Geminate Fusion of Correlated Triplets

    Seki, Kazuhiko / Ryuzi Katoh / Yoriko Sonoda

    Journal of physical chemistry. 2018 May 03, v. 122, no. 22

    2018  

    Abstract: Singlet fission (SF) has been extensively studied through the use of magnetic field effects and analyzed by the Johnson–Merrifield model or its extended models. We extended the Johnson–Merrifield model to study delayed fluorescence originating from ... ...

    Abstract Singlet fission (SF) has been extensively studied through the use of magnetic field effects and analyzed by the Johnson–Merrifield model or its extended models. We extended the Johnson–Merrifield model to study delayed fluorescence originating from diffusion-mediated reversible geminate fusion of triplets; the emission intensity was shown to decay by a A/tβ law, where β = 3/2 in one and three dimensions and β = 1 in two dimensions. Analytical expressions for the amplitude as well as the exponent of the asymptotic power law decay were obtained. We have shown that a wide range of SF materials from polyene-based molecular crystals to amorphous rubrene exhibit A/t3/2 asymptotic decay. The temperature dependence of the asymptotic emission decay supports a mechanism involving delayed fluorescence mediated by diffusion. Moreover, we show that the decay lines at different field strengths will not cross each other when fission occurs effectively. In the opposite limit when fusion occurs effectively the two decay lines will cross each other.
    Keywords crystals ; emissions factor ; fluorescence ; magnetic fields ; models ; physical chemistry ; temperature
    Language English
    Dates of publication 2018-0503
    Size p. 11659-11670.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1932-7455
    DOI 10.1021/acs.jpcc.8b02234
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: Intermolecular Dynamics of Perylene in Polymer Matrices during the Drop-Casting Process Probed by Fluorescence and Droplet Mass Changes

    Ito, Fuyuki / Kazuki Yamamoto / Ryuzi Katoh / Yoshiko Kogasaka

    Langmuir. 2018 June 18, v. 34, no. 28

    2018  

    Abstract: This work examines the drop-casting process of a perylene-doped polymer film by monitoring the changes in fluorescence and droplet mass. The mass is then used to estimate the mean intermolecular distance r(t) changes during the casting process. At a low ... ...

    Abstract This work examines the drop-casting process of a perylene-doped polymer film by monitoring the changes in fluorescence and droplet mass. The mass is then used to estimate the mean intermolecular distance r(t) changes during the casting process. At a low perylene concentration (0.01 mol %), the fluorescence band was maintained during and after the casting process of poly(methyl methacrylate) (PMMA), whereas the r(t) values suggested that the perylene dimer does not form. With an increase in the perylene concentration in the casting droplet, significant fluorescence changes were observed at an r(t) value of ∼3.0 nm; this was comparable to the Förster distance between the monomers. Fluorescence changes were attributed to energy migration from the monomer to the small amount of dimer species formed by fluctuation in solution (e.g., amplified quenching). The monomer fluorescence band decreased according to second-order kinetics after the formation of the excimer fluorescence band by molecular association. Following the decrease in monomer emission due to association, the excimer emission originated from the excitation of both the monomer and ground-state dimer. Fluorescence spectral changes did not reveal any significant dependence of the casting process on the polymer matrices. The minor changes of the fluorescence spectra originated from the reabsorption and segregation of the perylene crystals in the films, depending on the polymers (PMMA, polystyrene, and Zeonex) employed. This was attributed to the intermolecular interaction between perylene and the polymer side chains. Real-time monitoring of the mean distance of the dye during the casting process can provide a suitable fabrication process for functional polymer films by the spin and drop-casting methods. Moreover, the intermolecular dynamics for molecular assembly and nucleation and growth of crystals can be elucidated by studying the fluorescence changes.
    Keywords absorption ; chemical interactions ; crystals ; droplets ; energy ; films (materials) ; fluorescence ; fluorescence emission spectroscopy ; monitoring ; polymethylmethacrylate ; polystyrenes
    Language English
    Dates of publication 2018-0618
    Size p. 8281-8287.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/acs.langmuir.8b01342
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top