Unipolar Transport and Interface Charge Transfer in Nanostructured CdTe/polymer Hybrid Films

We report detailed photoconductance measurements on hybrid semiconductor films consisting of CdTe nanoparticles in a poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV) matrix. Our results show that a staggered band alignment between organic and inorganic semiconductors produces an efficient separation of photoexcited electron-hole pairs and promotes a unipolar transport in each of the semiconductors. Hole drift mobilities in the MEH-PPV film and electron drift mobilities in the CdTe nanoparticle network are determined. We find clear evidence for the transport in the two phases of the hybrid film to be electrically uncoupled, and we conclude that these properties can lead to improved electron transport properties