Structural and Optical characteristics of PVA:C-Dot composites: Tuning the absorption of Ultra Violet (UV) region

In this work the influence of carbon nano-dots (CNDs) on absorption of ultra violet (UV) spectra in hybrid PVA based composites was studied. The FTIR results reveals the complex formation between PVA and CNDs. The shifting was observed in XRD spectrum of PVA:CNDs composites compared to pure PVA. The strong absorption was observed in the absorption spectra of the composite samples. The intense absorption peaks appeared at 280 nm and 330 nm are ascribed to n-π* and π-π* transition. The absorption edge shifted to lower photon energy sides with increasing CNDs. The refractive index increased linearly with increasing CNDS concentration. The optical dielectric constant which is related to the density of states was studied. The optical dielectric loss parameter was used to study the optical band gap of the samples. Taucs model was used to determine the type of electronic transition in the samples.