Influence of KI salt concentration on the hydroxypropyl methylcellulose films: Optical study

Herein the optical properties of Hydroxypropyl methylcellulose/Potassium iodide (HPMC/KI) composite films were determined. The casting technique was introduced to make HPMC/KI with different KI salt concentrations (0.1–1) wt%. absorbance model used determine parameters like absorption edge, refractive index, real and imaginary sections dielectric function, extinction coefficient, Urbach energy, band gap, conductivity in spectral range 200–800 nm. As shown by study, doping affects HPMC. edge ( E e ) widely displaced towards a region lower photonic energy. direct indirect bandwidth gaps lowered from 5.6 2.56 eV 5.86 2.5 for 1 wt % film, respectively. loss method effectively employed as an alternate estimating gap. In addition, Tauc's extrapolation identified kind electronic transition. variation energy gap constant ε based on concentration investigate credibility Penn's model. salt-composite films, increase observed which may be evidence large shift tail-to-tail band-to-tail transitions. Meanwhile, X-ray diffraction (XRD) examination revealed that salts damaged HPMC polymer's crystalline phase. Lastly, subjected Fourier Transform Infrared Spectroscopy (FTIR). considerable transmittance change doped FTIR spectra. • small bandgap material is successfully achieved using solution cast technique. bandgap. check Penn’s model’s credibility. fine shows their suitability optoelectronics applications.