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Electroluminescence properties of conjugated polymers functionalized with calix[4]arenes

Matos, M. ; Morgado, J. ; Costa, A.C. ; Prata, J.V.P.

Electroluminescence properties of conjugated polymers functionalized with calix[4]arenes, Proc IUPAC Symposium on Photochemistry, Coimbra, Portugal, Vol. 0, pp. 0 - 0, July, 2012.

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Abstract
rganic light emitting diodes (OLEDs), including those based on polymers, show several advantages in display assemblies as compared to their inorganic counterparts. The solution processability, the possibility of making large and flexible areas of illuminating surfaces, the low fabrication costs and the production of devices capable of emitting most of the light colors are some of the outstanding features normally associated with these materials. This technology is now used as an illumination light source and backlight in LCD displays but new materials and different light color emissions are hot research topics. We produced OLEDs from new emissive calix[4]arene-based poly(p-phenylene ethynylene)s [1-2]. These materials show high solubility in several common organic solvents that allows the use of the simple and inexpensive spin coating technique for the device production.
The OLEDs were fabricated using our previous described techniques [3] by the successive deposition of the layers ITO/PEDOT:PSS/CALIX-PPE/metal (aluminum and calcium). The characteristics of the produced OLEDs are shown in figure. These OLED’s produce various light colors including a very interesting white emission with a good efficiency and show a typical light-onset voltage of 6V, reaching a maximum of luminance at 20 V.
The interesting properties observed in these OLEDs pave the way for the development of a diversity of other calixarene-based PPE polymer-OLEDs, which can be structurally tailored to match various light color emissions. The different light color emission can be achieved either by structurally changing the core chromophores or, much more easily, using the capability of different ion complexation by the calixarene scaffolds.