A novel electrically conducting polymer consisting of selenophene moiety, poly(biselenophene) (PBSE) was generated by chemical and electrochemical polymerization. This polymer gave lower bandgap energy (1.9 eV) than pristine polyselenophene (2.0 eV). The electrochemical and optical properties of PBSE was investigated by UV-Vis near infrared spectroscopy and electrochemistry. In situ electrochemical doping studies of PBSE showed the formation of polaron states at 1.4 and 0.8 eV. Through cyclic voltammetry, the polymer oxidation potential (E-pa) and reduction potential (E-pc) for p-doping process for PBSE were observed at 0.93 and 0.86 V, respectively, at a scan rate of 20 mV s(-1). Upon chemical doping using chemical reagents such as iodine and ferric chloride, a maximum conductivity of 0.1 S cm(-1) was achieved. (C) 2003 Elsevier Ltd. All rights reserved.