Synthesis characterization, optical and electrical properties of polyvinyl alcohol/multi-walled carbon nanotube nanocomposites: A composition dependence study

[Display omitted] •PVA/MWCNT nanocomposites have been synthesized by simple and low cost method.•Good interaction between MWCNT and PVA molecular chains.•Linear decrease of the nanocomposites band gap with MWCNT content.•Improved electrical properties have been obtained by adding MWCNT.•A percolation threshold was obtained at about 4 wt% of MWCNT.•The I-V characteristics have been simulated by the back to back Schottky models.•The ideality factors and barrier heights was calculated. Polyvinyl alcohol (PVA)/multi-walled carbon nanotubes (MWCNT) nanocomposites based films were synthesized by a facile pathway (solution casting method) with different weight ratios of MWCNT (0 wt%, 1 wt%, 3 wt%, 4 wt% and 5 wt%). FTIR measurements confirmed the interaction between MWCNT and PVA molecular chains. From UV–Visible spectroscopy study, the band gaps of PVA/MWCNT nanocomposites were calculated and we have observed a linear decrease with MWCNT addition. Photoluminescence (PL) spectroscopy study showed that the PVA emission is dominated by a broad band around 400 nm and decreases with MWCNTs content. The analysis of I-V characteristics shows an important current increase with MWCNT addition with a percolation threshold at about 4 wt%. Moreover, they have been simulated successfully with the established theory and have shown an ideality factor close to 1. These nanocomposites could be considered as promising candidates to be used in future nanotechnology based devices.