Kumar, Amit and Srivastava, Ritu and Bawa, Sukhwant S. and Singh, Devender and Singh, Kapoor and Chauhan, Gayatri and Singh, Ishwar and Kamalasanan, Modeeparampil N. (2010) White organic light emitting diodes based on DCM dye sandwiched in 2-methyl-8-hydroxyquinolinolatolithium. Journal of Luminescence , 130 (8). pp. 1516-1520. ISSN 0022-2313

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Stable white electroluminescence (EL) has been achieved from organic LED, in which an ultrathin 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM) dye layer has been inserted in between two 2-methyl-8-hydroxyquinolinolatolithium [LiMeq] emitter layer and by optimizing the position of the DCM dye layer from the α-NPD/LiMeq interface. Electroluminescence spectra, current–voltage–luminescence (I–V–L) characteristics of the devices have been studied by changing the position of the dye layer. As the distance of DCM layer from α-NPD/LiMeq interface is increased, the intensity of host emission enhances rapidly. Introduction of thin layer of DCM in emissive layer increases the turn on voltage. The best Commission International de L’ Eclairage (CIE) coordinates i.e. (0.32, 0.33) were obtained with device structure ITO/α-NPD(30 nm) /LiMeq(10 nm)/DCM(1 nm)/LiMeq(25 nm)/BCP(6 nm)/Alq3(28 nm)/LiF(1 nm)/Al(100 nm). The EL spectrum covers the whole visible spectra range 400–700 nm. The color rendering index (CRI) for our best white light (Device 4) is 47.4. The device shows very good color stability in terms of CIE coordinates with voltages. The maximum luminescence 1240 cd/m−2 has been achieved at 19 V.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s Elsevier B.V.
Uncontrolled Keywords: WOLED; 2-methyl-8-hydroxyquinolinolatolithium; Sandwiched; Exciplex
Subjects: Optics
Depositing User: Ms Neetu Chandra
Date Deposited: 08 Aug 2012 11:14
Last Modified: 08 Aug 2012 11:14
URI: http://npl.csircentral.net/id/eprint/392

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