Study of 160 MeV Ni 12+ ion irradiation effects on electrodeposited polypyrrole films A.M.P. Hussain a, * , A. Kumar a , D. Saikia a , F. Singh b , D.K. Avasthi b a Department of Physics, Tezpur University, Napaam, Tezpur, Assam 784 028, India b Nuclear Science Centre, Aruna Asaf Ali Marg, New Delhi 110 067, India Received 26 April 2005; received in revised form 14 June 2005 Available online 15 August 2005 Abstract Conducting polymer polypyrrole thin films doped with LiCF 3 SO 3 , [CH 3 (CH 2 ) 3 ] 4 NBF 4 and [CH 3 (CH 2 ) 3 ] 4 NPF 6 have been electrodeposited potentiodynamically on ITO coated glass substrate. The polymer films are irradiated with 160 MeV Ni 12+ ions at three different fluences of 5 · 10 10 ,5 · 10 11 and 3 · 10 12 ions cm 2 . An increase in dc conduc- tivity of polypyrrole films from 100 S/cm to 170 S/cm after irradiation with highest fluence is observed in four-probe measurement. X-ray diffractogram shows increase in the crystallinity of the polypyrrole films upon SHI irradiation, which goes on increasing with the increase in fluence. Absorption intensity increase in the higher wavelength region is observed in the UV–Vis spectra. The SEM studies show that the cauliflower like flaky microstructure of the surface of polypyrrole films turns globular upon SHI irradiation at fluence 5 · 10 11 ions cm 2 and becomes smooth and dense at the highest fluence used. The cyclic voltammetry studies exhibit that the redox properties of the polypyrrole films do not change much on SHI irradiation. Ó 2005 Elsevier B.V. All rights reserved. PACS: 73.61.Ph; 61.10.Nz; 68.37.Hk; 33.20.Lg; Ni; 33.20.Ea Keywords: Conducting polymers; Polypyrrole; Swift heavy ion irradiation; Cyclic voltammetry; UV–Vis; XRD and SEM 1. Introduction Research interest in the electronically conduct- ing polymers are growing because of their poten- tial applications as sensors [1,2], field effect transistors [3–5], light-emitting diodes [6–10] pho- todetectors [11] photovoltaic cells, [12–15], lasers (solution [16,17] and solid-state [18–22]), actuators [23,24], smart windows [25] and electrode materials for charge storage devices such as supercapacitors and rechargeable batteries for their high specific capacitance and high dc conductivity in the 0168-583X/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2005.06.211 * Corresponding author. Tel.: +91 3712 267007–9x5597; fax: +91 3712 267005/6. E-mail address: abu@tezu.ernet.in (A.M.P. Hussain). Nuclear Instruments and Methods in Physics Research B 240 (2005) 871–880 www.elsevier.com/locate/nimb