Investigation on the Optical and Surface Morphology of Conjugated Polymer MEH‐PPV:ZnO Nanocomposite Thin Films

Abstract

Thin films of red color poly(2‐methoxy‐5(2′‐ethylhexyloxy)‐phenylene vinylene) (MEH‐PPV) containing different weight percent of ZnO nanoparticles were obtained by spin‐coating techniques. The MEH‐PPV:ZnO solutions were spin coated onto silicon and glass substrates. The spun MEH‐PPV:ZnO thin films were then used to investigate optical properties by using ultraviolet‐visible spectrometer (UV‐Vis) and photoluminescence spectrophotometer (PL). The morphologies were investigated by using field emission scanning electron microscopy (FESEM), while the identification of ZnO in the final product was determined by using energy‐dispersive X‐ray spectroscopy (EDS). The UV‐Vis absorption band increases, while the optical bandgap decreases when the amount of ZnO nanoparticles increases. ZnO nanoparticles apparently have no effect on the conjugation segments of MEH‐PPV. PL spectra show that the emission peak increases and slightly red shift as ZnO concentration increases. Based on SEM images of MEH‐PPV:ZnO nanocomposite thin films, ZnO nanoparticles form agglomerated regions.