Influence of heating temperature on electrical photoconductivity of nanocomposited polymer-Tio2 thin films for organic photovoltaic

The influence of heating temperature on the properties of nanocomposited poly [2-methoxy 5-(2´-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV) polymer and titanium dioxide (TiO₂) thin films has been investigated. The heating temperature was varied from 50°C, 75°C, 100°C, 125°C and as deposited thin films as reference sample. Compared with a pristine thin film (as deposited) the MEH-PPV: TiO₂ heated thin film shows an improved in current-voltage, conductivity and absorbance characteristics. The variation in heating temperature has affect to the reduction of series resistance of the thin film and therefore improves the photoconductivity from 2.134×10^-6 to 6.656×10^-6 S.cm^-1. The absorbance also shows an improvement as upon heating, the absorption spectrum of the MEH-PPV: TiO₂ nanocomposite undergoes a modification compared to as deposited thin film which remains unchanged. The absorption of the heated nanocmposited thin films shows a significant red-shifted in the wavelength region ascribed to MEH-PPV (500 nm) while the absorption due to TiO₂ (340 nm) does not change. Optimization of heating temperature plays a significant role for conductivity properties of nanocomposite MEH-PPV: TiO₂.