Electroluminescence Enhancement of Polymer Light Emitting Diodes Through Surface Plasmons by Ag Nanoplates
T.H.T. Aziz, M.M. Salleh, N.A. Bakar, A.A. Umar and M.Y.A. Rahman
Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
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This paper reports a study on the surface plasmon effect of Ag nanoplates on electroluminescent property of polymer light emitting diodes. The diode is a single layer light emitting device made of poly [9,9-di-(2-ethylhexyl)-fluorenyl-2,7-diyl] (PEHF). 5 wt.% of Ag nanoplates were incorporated into the PEHF layer. The results showed that the electroluminescence intensity of the diodes is increased by 51.85%, compared with the device without the Ag nanoplates. The enhancement is due to the coupling process between the Ag surface plasmon with the emission light from the PEHF. The occurrence of the coupling process was proved firstly based on the fact that the exciton lifetime of the PEHF:Ag layer is shorter than that without Ag, as measured by time-resolved photoluminescence spectroscopy. Secondly, the PEHF photoluminescence peak at 425 nm is overlaping with the surface plasmon absorption peak of Ag nanoplates.

DOI: 10.12693/APhysPolA.129.711
PACS numbers: 73.20.Mf