Optical properties of MEH-PPV thin films containing ZnO nanoparticles

In this paper, composites made by incorporation of ZnO nanoparticles of different concentrations in MEH-PPV was studied. MEH-PPV is a soluble conjugated polymer, one can incorporate oxide nanoparticles into MEH-PPV directly. Optical properties of the hybrid materials and the influence of the nature on the behavior of the composites was investigated and discussed. The polymer was dissolved in tetrahydrofuran (THF) to form solution with concentration of 1 mg/ml. Composite samples were prepared by adding ZnO nanoparticles to MEH-PPV solutions with different weight ratios and thin films were prepared by spin coating onto glass substrate. Optical measurements of the samples were measured by using UV-Vis spectrophotometer and the thickness of the samples was measured with surface profiler. The conjugation length of polymer is not affected by the presence of the particles.The thin films optical band gap increased due to ZnO nanoparticles contribution and been supported by Burstein-Moss effect. From the Burstn-Moss effect support the widening of the band gap due to the carrier concentration. The wide band gap is one of the promising characteristics for applications of opto-electronics devices since it lowered the leakage current, high break down voltages, and high electron mobility.