Study of nanostructured polymeric composites used for organic light emitting diodes and organic solar cells

Polymeric nanocomposite films from PEDOT and MEH-PPV embedded with surface modified TiO₂ nanoparticles were prepared, respectively for the hole transport layer (HTL) and emission layer (EL) in Organic Light Emitting Diodes (OLED). The composite of MEH-PPV + nc-TiO₂ was used for Organic Solar Cells (OCS). The results from the characterization of the properties of the nanocomposites and devices showed that electrical (I-V characteristics) and spectroscopic (photoluminescent) properties of the conjugate polymers were enhanced due to the incorporation of nc-TiO₂ in the polymers. The OLEDs made from the nanocomposite films would exhibit a larger photonic efficiency and a longer lasting life. For the OSC made from MEH-PPV + nc-TiO₂ composite, the fill factor (FF) reached a value as high as 0.34. Under illumination of light with a power density of 50 mW/cm², the photoelectrical conversion efficiency (PEC) was found to be of 0.15% corresponding to an open circuit voltage V_OC = 1.15 V and a short-cut circuit current density J_SC = 0.125 mA/cm².