%0 Journal Article
%T White Light Electroluminescence by Organic-Inorganic Heterostructures with CdSe Quantum Dots as Red Light Emitters
%A Ilker Oner
%A Elias Stathatos
%A Canan Varlikli
%J Advances in Optical Technologies
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/710628
%X We have developed a white organic light-emitting diode featuring a double emission layer comprising a blue light-emitting conductive polymer as a host material for Cadmium Selenide (CdSe) quantum dots as red light emitters and tris-(8-hydroxyquinoline) aluminium thin layer for green light emission. The Commission Internationale de l'Eclairage coordinates of the emitting light of the device were found to be (0.32,£¿0.40) which were only slightly changed over a range of applied voltages between 5 and 10 volts. The use of CdSe nanocrystalline quantum dots (surface-stabilized with hexadecylamine/trioctylphosphine oxide ligands) in the hybrid heterostructure with poly(9,9-di-n-octylfluorenyl-2,7-diyl) conductive polymer was studied for a variety of CdSe concentrations developing the performance of the device in means of overcoming segregation problems in the blend. Besides, constituents' ratio was further examined for the exploration of possible energy transfer from polymer host material to the CdSe quantum dots as a key factor for well-balanced emission in the electroluminescent devices. 1. Introduction Electroluminescence as a result of radiative recombination of electrons and holes in an inorganic semiconducting material is a well-known phenomenon for many years with a variety of applications usually in common LEDs [1]. The use of organic semiconductors either in form of conjugated polymers or small molecules is a more recent technological development of the initial idea. Since the first announcement of organic light-emitting diodes (OLEDs) [2] and polymer-based light-emitting diodes (PLEDs) [3] an extensive research has been established which led these devices to the commercialization stage [4, 5]. The basic advantage of these devices is the easy fabrication process using a variety of small molecules [6] or conductive polymers [7] where common deposition techniques such as dip coating, spin casting, and inkjet printing are used. Furthermore, the variety of conductive organic materials and new trends in materials¡¯ modification has led the OLED technology to present high-efficiency devices with long-term stability in a variety of emitting colours and turn-on voltages [8¨C10]. However, the most attractive emitting colour in LED industry is the white colour as it may offer many benefits in lighting technology including energy saving (e.g., flashlights, architectural lighting, displays backlighting, and large area displays). The fabrication of a white emitting LED based on organic materials (WOLED) is an attractive idea which was developed in very recent years
%U http://www.hindawi.com/journals/aot/2011/710628/