Please cite this article in press as: S. Biswas, et al., Consequence of silver nanoparticles embedment on the carrier mobility and space charge limited conduction in doped polyaniline, Appl. Surf. Sci. (2013), http://dx.doi.org/10.1016/j.apsusc.2013.11.154 ARTICLE IN PRESS G Model APSUSC-26810; No. of Pages 12 Applied Surface Science xxx (2013) xxx–xxx Contents lists available at ScienceDirect Applied Surface Science j ourna l ho me page: www.elsevier.com/locate/apsusc Consequence of silver nanoparticles embedment on the carrier mobility and space charge limited conduction in doped polyaniline Swarup Biswas a , Bula Dutta b , Subhratanu Bhattacharya a,∗ a Department of Physics, University of Kalyani, Kalyani, Nadia, 741235, India b Department of Chemistry, P. D. Women’s College, Jalpaiguri 735101, West Bengal, India a r t i c l e i n f o Article history: Received 23 June 2013 Received in revised form 23 November 2013 Accepted 29 November 2013 Available online xxx Keywords: Silver polyaniline nanocomposites Space charge limited conduction Electric field and temperature dependent mobility a b s t r a c t The present study depicts a one-pot strategy to fabricate silver-polyaniline hybrid nanocomposites with superior and tunable electrical properties, supported by structural characterizations and detail analysis of their temperature dependent current density (J)–voltage (V) characteristics. TEM micrographs clearly reveal that the nanocomposites synthesized by this one-pot strategy contain higher dispersion of sliver nanoparticle within the polyaniline matrix with respect to that obtained from the embedment of exter- nally pre-synthesized silver nanoparticles. The results obtained from the analysis of J–V characteristics indicate the prevalence of trapped charge-limited conduction mechanism in doped polyaniline and its nanocomposites. For the nanocomposites obtained from one-pot strategy, a transition of charge transport mechanism from deep exponential trap limited to shallow traps limited conduction has been occurred due to higher dispersion of silver nanoparticles within the polyaniline matrix. Such distinct variation of charge conduction is absent in the nanocomposites obtained from the embedment of externally pre- synthesized silver nanoparticles. A direct evaluation of carrier mobility as a function of electric field and temperature illustrates that the incorporation of only ∼13 to 18 wt% of silver nanoparticles within the polyaniline matrix enhances the carrier mobility in a large extent by reducing the concentration of traps within the polymer matrix. The calculated mobility is consistent with the Poole–Frenkel form for the electrical field up to a certain temperature range. The nonlinear low temperature dependency of mobil- ity of all the nanostructured samples has been explained by Mott variable range hopping conduction mechanisms. Qualitative estimation of various disorder parameters such as optimal hopping distance, localization lengths etc., would help us to outspread the strategies for the fabrication of new organic semiconducting nano-structured devices. © 2013 Elsevier B.V. All rights reserved. 1. Introduction For application of conjugated polymers, their behavior in an electric field is a long-standing problem and of great importance. These electrically conducting polymers are capable of electrical charge transfer to the same extent as an electrical conductor or a semiconductor. Due to their interesting electrical and optical properties, they have played crucial roles in specialized industrial applications in spite of their short antiquity. In order to improve and extend the functions of conducting polymers, the synthesis of functionalized conducting polymer com- posites with the incorporation of metal nanoparticles has attracted a great deal of attention during the last decades [1,2]. With com- bined features of the parent constituents, these composites are often called as hybrid materials. ∗ Corresponding author. Tel.: +91 33 2582 0184; fax: +91 33 2582 8282. E-mail address: subhratanu1@gmail.com (S. Bhattacharya). It is reported [3–7] that electrical properties of metal- conducting polymer hybrid nanocomposites are significantly dependent upon the mutual proportions of the metal nanoparticles to the organic counterparts and their morphology and the introduc- tion of silver nano-particles to the matrices of different conducting polymer such as polyaniline or polypyrrole, generally leads to an improvement in their electrical properties [5–11]. In the classi- cal percolation concept, approximately 50–60 mass% of the metal nano-particles in the polymer matrix is needed for the formation of metallic conducting pathways in the three-dimensional composite i.e. for the percolation threshold. In this case the most conduct- ing elements are metals and conductivity is therefore very high [10,11]. Below the percolation threshold, the dispersed nanopar- ticles within the conducting polymer matrices play the role of conducting filler to reinforce their overall electrical properties [5,7–9]. Both the conducting polymers and silver display a variety of morphologies and size distribution on the nanoscale. Their nature, distribution within the composites, morphology and interfacial 0169-4332/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.apsusc.2013.11.154