• Effect of adsorption of vapours on the electrical conductivity of some polyene semiconductors: adsorption and desorption kinetics

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      https://www.ias.ac.in/article/fulltext/jcsc/089/02/0209-0217

    • Keywords

       

      Organic semiconductors; vapour adsorption effect; desorption kinetics; adsorption kinetics; electrical conductivity; polyene semiconductors

    • Abstract

       

      The change in semiconductive properties of β-apo-8′-carotenal, astacene and methyl bixin on adsorption of various vapours on the crystallite surfaces has been studied at a constant sample temperature. The adsorption of vapours enhances the semiconductivity of the polyenes appreciably. This enhancement depends on the chemical nature and also on the pressure of the adsorbed vapour. The adsorption and desorption kinetics follow the modified Roginsky-Zeldovich relation. A two stage desorption process, the first stage of which gives a Lennard-Jones potential energy curve and is followed by a rate-determining transition over a potential energy barrier to the second stage of adsorption forming weakly bound complexes between the vapour molecules and the polyene crystallites, can explain satisfactorily the experimentally observed kinetic data.

    • Author Affiliations

       

      Alpana Ghosh1 Biswanath Mallik1 T N Misra1

      1. Optics Department, Indian Association for the Cultivation of Science, Jadavpur, Calcutta - 700 032, India
    • Dates

       
  • Journal of Chemical Sciences | News

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