Charge transport in thin films of MDMO PPV dispersed with lead sulfide nanoparticles

Abstract

Enhanced hole mobility is observed in thin films of poly(2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene) (MDMO PPV) dispersed with Lead Sulfide nanoparticles. Changes in the polymer film morphology upon the dispersion of nanoparticles and its influence on the enhancement of carrier mobility is investigated using Photoluminescence (PL) and Raman spectroscopic studies. PL and Raman studies show that at low concentrations of nanoparticles there is an enhancement in polymer interchain interaction. At higher concentrations, the interhain interaction decreases. Raman studies show that the observed enhancement of polymer interchain interaction at low nanoparticle concentration is due to the tighter packing of polymer chains. Thus, at low nanoparticle concentration, the observed increase in mobility is assigned to both the enhancement in interchain interaction and tunneling of carriers through nanoparticles. At higher nanoparticle concentrations the observed enhancement of mobility can be totally attributed to the tunneling of carriers through nanoparticles.