Charge transport in two different conductive polymer and semiconducting quantum dot nanocomposite systems

Charge transport mechanisms have been investigated in two different nanocomposite structures made of conductive polymers embedded with II-VI semiconducting quantum dots. Photoluminescence data indicated charge transport in the two systems. Higher photocurrents observed in the poly (3-hexylthiophene-2,5-diyl) polymer-based heterostructure in comparison with the poly(2-methoxy-5 -(20-ethyl-hexyloxy)-1,4-phenylenevinylene) polymer-based heterostructure have been analyzed with hole and electron conduction. For larger concentrations of quantum dots, both electron transport through nanocrystals and hole transport through polymer become relevant. Based on the electron tunneling mechanism, current voltage characteristics are modeled for a double barrier quantum well device formed by semiconducting quantum dots and polymer molecules.