標題: Investigations of organic light emitting diodes with CdSe(ZnS) quantum dots
作者: Lee, C. W.
Chou, C. H.
Huang, J. H.
Hsu, C. S.
Nguyen, T. P.
應用化學系
Department of Applied Chemistry
關鍵字: organic light emitting diodes;quantum dots;co-polymer;cadmium selenide
公開日期: 15-Feb-2008
摘要: In this study, we report results on investigation of bilayer light emitting diodes made of organic capped CdSe(ZnS) core/shell type nanocrystals and poly [2-phenyl-3-(9,9-dihexyl-fluoren-2-yl) phenylene vinylene]-co-[2-methoxy-5-(2'-ethylhexyloxy) phenylene vinylene] (FP-PPV-co-MEH-PPV) electroluminescent co-polymer. Light emitting diodes of structure: indium-tin-oxide (ITO)/polyethylene dioxythiophene: polystyrene sulfonate (PEDOT:PSS)/FP-PPV-co-MEH-PPV/Ca/Al devices have been fabricated and studied. The co-polymer device emits a yellow light with a maximum brightness of 3949 cd/m(2) and a maximum external quantum efficiency of 0.27 cd/A at 10 V. Incorporation of CdSe(ZnS) quantum dots into the active polymer film resulted in an increase in device brightness, which reached 8192 cd/m(2) and in external quantum efficiency, which became 1.27 cd/A at 7 V with a lower turn-on voltage. The results indicate that CdSe(ZnS) quantum dots improved significantly the emission of the devices by modifying the injection and transport of the charge carriers. We suggest a non-uniform dispersion of QDs in the co-polymer layer with carrier blocking process by the particles, which produced a balanced charge distribution inside the co-polymer, and thus increased the emission efficiency. (c) 2007 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.mseb.2007.09.068
http://hdl.handle.net/11536/30131
ISSN: 0921-5107
DOI: 10.1016/j.mseb.2007.09.068
期刊: MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY
Volume: 147
Issue: 2-3
起始頁: 307
結束頁: 311
Appears in Collections:Conferences Paper


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