Electrical and optical properties of light emitting electrochemical cells using MEH-PPV/PEO : lithium-salt blends

Light emitting electrochemical cells (LECs) were prepared with poly[2-metho xy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and poly(ethylen e oxide) (PEO) complexed with lithium triflate (CF3SO3Li) in different blen d compositions. Atomic force microscopy (AFM) images were performed to obse rve the influence of the blend composition in the film morphology. UV-Vis a bsorption and photoluminescence spectra were used to characterize the blend s, and current-voltage curves and electroluminecent measurements were carri ed out to study the device performance. A correlation between the blend mor phology and the electrical performance of the devices were also studied. Op tical and electrical results of LEDs made of pure MEH-PPV were presented fo r comparison with the LEC devices.