title: Traps and performance of MEH-PPV/CdSe(ZnS) nanocomposite-based organic light-emitting diodes.
abstract: We report the fabrication and investigations of organic light-emitting diodes (OLEDs) using a composite made by mixing poly[2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with CdSe/ZnS core/shell quantum dots (QDs). The electroluminescence efficiency of the studied devices was found to be improved as compared to devices using MEH-PPV. Moreover, the current density decreased with increasing QD concentration. We checked the effects of QDs on the electrical transport by determining the trap states, making use of the charge-based deep level transient spectroscopy (Q-DLTS) technique. The most striking result obtained is the decrease in trap density when adding QDs to the MEH-PPV polymer film. These results suggest that QDs would heal defects in nanocomposite-based devices and that CdSe/ZnS QDs prevent the trap center formation.
authors.affiliation: Institut des Matériaux Jean Rouxel, Université de Nantes-CNRS, 2 rue de la Houssinière, BP32229, 44322 Nantes, France. Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Lee
authors.forename: Cedric
authors.initials: C
authors.lastname: Renaud
authors.forename: Chain-Shu
authors.initials: CS
authors.lastname: Hsu
authors.forename: Thien-Phap
authors.initials: TP
authors.lastname: Nguyen