Synthesis, photophysical, electrochemical and computational study of indolocarbazole based donor acceptor type conjugated polymers

This research reports the synthesis and characterization of two new donor–acceptor type conjugated polymers carrying indolocarbazole as donor, benzothiadiazole and diketopyrrolopyrrole as acceptor via stille coupling polymerization reactions. The structures of the polymer were established by spectroscopic techniques and polymer molecular weight by gel permeation chromatography. Further the linear optical and electrochemical properties of the polymers have been investigated. Polymers showed broad absorption and good fluorescence behaviour with good quantum yields. Optical bandgaps of the polymers were estimated using UV–visible absorption edge and found to be 2.34 and 2.12 eV respectively. Further, theoretical evaluation of the polymers was carried using density functional theory to investigate their geometrical, electrochemical and optical properties using DFT/B3LYP. The obtained results are in good agreement with the experimental results.