Tyagi, Priyanka and Tuli, Suneet and Srivastava, Ritu (2015) Study of fluorescence quenching due to 2, 3, 5, 6-tetrafluoro-7, 7 ', 8, 8 '-tetracyano quinodimethane and its solid state diffusion analysis using photoluminescence spectroscopy. Journal of Chemical Physics, 142 (5). ISSN 0021-9606

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Abstract

In this work, we have studied the fluorescence quenching and solid state diffusion of 2, 3, 5, 6-tetrafluoro-7, 7', 8, 8'-tetracyano quinodimethane (F4-TCNQ) using photoluminescence (PL) spectroscopy. Quenching studies were performed with tris (8-hydroxyquinolinato) aluminum (Alq(3)) in solid state samples. Thickness of F4-TCNQ was varied in order to realize different concentrations and study the effect of concentration. PL intensity has reduced with the increase in F-4-TCNQ thicknesses. Stern-Volmer and bimolecular quenching constants were evaluated to be 13.8 M-1 and 8.7 x 10(8) M-1 s(-1), respectively. The quenching mechanism was found to be of static type, which was inferred by the independent nature of excited state life time from the F-4-TCNQ thickness. Further, solid state diffusion of F-4-TCNQ was studied by placing a spacing layer of alpha-NPD between F-4-TCNQ and Alq(3), and its thickness was varied to probe the diffusion length. PL intensity was found to increase with the increase in this thickness. Quenching efficiency was evaluated as a function of distance between F-4-TCNQ and Alq(3). These studies were performed for the samples having 1, 2.5, and 5.5 nm thicknesses of F-4-TCNQ to study the thickness dependence of diffusion length. Diffusion lengths were evaluated to be 12.5, 15, and 20 nm for 1, 2.5, and 5.5 rim thicknesses of F-4-TCNQ. These diffusion lengths were found to be very close to that of determined by secondary ion mass spectroscopy technique.

Item Type:	Article
Subjects:	Chemistry > Physical Chemistry Physics > Atomic and Molecular Physics
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	21 Oct 2016 05:16
Last Modified:	21 Oct 2016 05:16
URI:	http://npl.csircentral.net/id/eprint/2012

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