Investigation on photoconductive properties of MEH-PPV/CdSe-nanocrystal nanocomposites

The photoconductive properties of photodiodes based on nanocomposites of water-soluble CdSe nanocrystals and poly[2-methoxy-5-(2-ethylhexyloxy-p-phenylenevinylen)] (MEH-PPV) were investigated. The photoluminescence intensity of the nanocomposites decreased with the increasing weight ratios of CdSe nanocrystals to MEH-PPV. By comparing the photocurrent action spectra of the nanocomposite device and the pristine MEH-PPV device, it was found that the nanocomposite device exhibited a wider photocurrent action range. In addition, the nanocomposite device displayed an obvious photovoltaic effect upon illumination. The process of exciton dissociation and charge transfer between the interface of CdSe nanocrystals and MEH-PPV was discussed.