Hole transport and current–voltage characteristics of PEO / PVP /cobalt nitrate polymer blend electrolytes

Abstract Hole transport properties and Current–Voltage characteristics of the single‐layer device in an inverted structure were investigated with spin‐coated PEO/PVP/Cobalt nitrate polyblend electrolyte film as an active layer. A strong correlation between morphology and ionic conductivity was confirmed through XRD, DSC‐TGA, SEM and fluorescence spectroscopic techniques. The optical band gap values are in good agreement with the electrochemical band gap. Schottky diode measurements confirmed the formation of p‐type semiconductors with PEO/PVP bulk films with cobalt nitrate as a dopant at room temperature. The I‐V characteristics are strongly dependent on the salt concentration in the polymer blend. The parameters of diodes such as barrier height, saturation current, and charge carrier concentration were calculated from I‐V characteristics. From C‐V characteristics a charge carrier concentration in the range of 10 22 cm −3 was obtained for the highest concentration of cobalt nitrate salt in the PEO/PVP blend. A very low energy barrier for hole injection at the anode ΔE h = 0.28 eV was observed.