Investigation of the effect of two dyes on organic light emitting diodes electroluminescence

Abstract: In this article, two organic light emitting diodes OLEDs have been fabricated and studied. Poly(9-vinylcarbazole) PVK doped with Rhodamine 6G and Carbocyanine dyes at weight concentration of 2% has been used as a hole transporting luminescent layer. Each film was sandwiched between indium tin oxide (ITO) and aluminum (Al) layers. The measurements include I-V characteristics and variation of relative light intensity with the driving voltage and with the current. It is found that the threshold voltage (V_T) of the samples is smaller than that obtained in such PVK-based devices, when the PVK film is obtained by spin coating. The thickness of doped layer as well as the optical parameters has been determined using variable angle spectroscopic ellipsometer.

Keywords: Topological Organic light emitting diodes, PVK, Electroluminescence, ellipsometry.