Structural investigation of the enhanced electrical, optical and electrochemical properties of MWCNT incorporated Poly [3-hexylthiophene-2,5-diyl] composites

A small amount of MWCNT incorporated into the Poly [3-hexylthiophene-2,5-diyl] (P3HT) matrix can vary its structure as well as properties. P3HT/Multiwalled carbon nanotubes (MWCNT) composite films with variable MWCNT wt% have been prepared by simple solution processing method followed by spin coating. Structural investigations of the prepared P3HT/MWCNT composites by x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared (FFIR), Raman and UV Visible spectroscopy inferred the increase in conjugation length of the polymeric chain due to MWCNT incorporation. Cyclic-voltammetry study of the composites revealed a shift in the electronic band edges as well as a decrease in bandgap in composites compared to pristine P3HT that plays a significant role in optoelectronic devices. The shift in the electrochemical band edges in the composites has been attributed to the interfacial interaction between P3HT and MWCNT in the composites. The observed changes in the optical, electrical and electrochemical properties have been investigated and discussed in detail based on pronounced structural changes induced by MWCNTs in the composites. The observed results are important for organic photovoltaics as well as other optoelectronic devices. (C) 2017 Elsevier B.V. All rights reserved.