Organic ligand capping of CuI for enhanced electrical and ionic conductivity

Green synthesis of copper iodide from Jamun seed extract (Syzygium cumini) is done and capped with 2-mercaptobenzothiazole (MBT). The structural, morphological, optical and electrochemical properties of capped and uncapped CuI were compared. Optical studies indicate 0.34 eV decrease in the bandgap of CuI upon capping with MBT. Electrochemical Impedance Analysis (EIS) revealed four orders of magnitude increase in the electrical conductivity and two times increase in ionic conductivity upon capping by MBT. This lowering of band gap and higher electrical conductivity for CuI–MBT makes it a suitable material for optoelectronic devices and thin film solar cell applications in comparison with uncapped CuI.