Nanostructural, optical and heterojunction characteristics of PEDOT™/ZnO nanocomposite thin films

Poly(3,4-ethylenedioxythiophene), Tetra Methacrylate (PEDOT™)/ZnO nanocomposite thin films were fabricated by the conventional spin coating method and characterized by X-ray diffraction technique. The results indicated that ZnO nanopowder has a polycrystalline nature with a hexagonal system and mean crystallite size of 53.1 nm. The main important optical parameters were extracted by using the spectrophotometer methodology covering the range of 200–2500 nm. A direct allowed transition with the onset and fundamental energy gaps were found to be 1.9 and 3.9 eV. The current density-voltage characteristics of PEDOT™/ZnO nanocomposite film/n-Si heterojunction showed diode-like behavior. Temperature dependence of series and shunt resistances was investigated. The high value of ideality factor (η) can be referred to the influence of an interfacial layer. Temperature dependence of barrier height indicated the presence of inhomogeneous barrier at an interface which is considered to be the reason for the observed behavior of the barrier height with temperature.