Optical band gap of nanocompsoite MEH-PPV:TiO2 thin film

In this paper, the white pigment TiO₂ powder was first annealed at 450 °C before mixing it to the polymer solution to ensure that the TiO₂ was in its anatase phase. The 50 mg MEH-PPV polymer was dissolved in tetrahydrofuran with a concentration of 1:1. The composite materials were prepared by adding appropriate amounts of TiO₂ powder (5 wt%, 10 wt%, 15 wt% and 20 wt%) into the polymer solution to make various ratios of TiO₂ powder/polymer composites. The optical band gap and surface morphology of nanocomposite conjugated polymer MEH-PPV:TiO₂ were investigated. The purpose of doing this research is to investigate if there is optical band gap decrement when the composition of TiO₂ powder is increased.