Comparison of the optical and electrical energy band gap of a thin layer of polyelectrolyte based on MEH-PPV and KI

Abstract A thin layer of polyelectrolyte based on Poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) and potassium iodide (KI) was prepared using the sol-gel method. Comprehensive studies of the optical and electrical energy gap of the produced material were carried out. Using the Thermo Scientific Evolution 220 spectrophotometer equipped with a xenon lamp in the wavelength range from 190 to 1110nm, the absorbance A was measured. The optical energy gap (Egopt) was calculated. With the change in the concentration of potassium iodide, the change in the energy band gap of polyelectrolyte thin film was registered. In this paper, the cyclic voltammetry (CV) for testing electrochemical properties was used. The location of energy levels HOMO, LUMO and the value of the energy band gap were calculated, which is very important for polymeric materials that conduct electricity and the possibility of their use in solar cells.