Simple processed polyvinyl alcohol/multi-wall carbon nanotube polymeric nanocomposites for high-performance optoelectronics

Nanocomposites of polyvinyl alcohol (PVA)/multi-wall carbon nanotube (MWCNT) were prepared using the simple solution cast technique with different contents of MWCNT (0, 0.05, 0.25, 0.5, and 1( wt%. XRD confirmed the semi-crystalline character of PVA structure which is slightly affected by adding MWCNT. At wavelengths between 200 and 2500 nm, optical characteristics are investigated. A decrease was seen in the optical energy band gap (E_g) with the inclusion of MWCNTs for both the allowed indirect and direct transitions. A normal dispersion within the examined wavelength domain was provided by an analysis of the index of refraction (n). The decrement in the band gap (E_g) and the increment in the index of refraction n due to addition of MWCNT suggests their use in optical devices. At RT, the dielectric constant ɛ′, loss ɛ″, and ac conductivity σ_ac were found to depend on frequency (100 Hz–1 MHz) and MWCNT concentration. The PVA films tend to have higher σ_ac when MWCNT is added, which may serve in several semiconductor applications. The optical power limiting results indicated that PVA samples containing MWCNT could attenuate the He–Ne laser beam (λ = 638.2 nm). The results demonstrate the utility of PVA-MWCNTs nanocomposite materials in various applications such as UV shielding, photo sensors, tunable band gap devices, refractive index-controlled optical devices, and next-generation flexible optoelectronic devices.