Fabrication of a Near Infrared OLED Using a New Organic Chromophore Mohammad Taghi Sharbati 1 , Farzin Emami 1 , Alireza Gharavi 2 , Farhad Panahi 3 1 Department of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Iran 2 Photonic Laboratories, School of Electrical and Computer Engineering, Shiraz University, Shiraz, Iran 3 Department of Chemistry, Persian-Gulf University, Boushehr, Iran Abstract- We have fabricated a single-layer near infra-red organic light emitting diodes by a new luminescent material. The characteristics of this diode is measured and investigated with different thicknesses. Electroluminescence is observed with the peak at 800 nm. Keywords: Organic light emitting diode (OLED), single layer OLED, near-infrared (NIR) emission spectrum, i-v curve. 1. INTRODUCTION In recent years, organic light-emitting diodes (OLEDs) are considered as a new kind of full-color flat-panel displays technology after the initial works done by Tang and VanSlyke [1]. Also, in display technologies organic light emitting diodes show great advantages such as low cost, small size, flexible flat screens [2],[3], with better resolution and wider viewing angles than LCD displays [4]. No need for backlight, higher brightness and low power consumption are other important specifications of OLEDs [1]. OLEDs in the visible spectrum region have achieved significant progress since 1987 [1]. Near- infrared (NIR) and infrared (IR) OLEDs have also received growing attention because of their applications in information processing [5] and night-vision readable displays [6]. So far, the IR and NIR organic light-emitting materials that have been reported include organic ionic dyes, organic molecules, organic rare-earth complexes, and organic ligands and semiconductor nano particles with organic substituents [7]-[15]. In the mean time, the red light-emitting materials have remained to be the weakest part in realizing the full color display. Low electroluminescence (EL) efficiency and impure EL spectrum due to the existence of visible light in NIR emission limit are the other practical applications of OLEDs [7], [9]. II. EXCREMENTAL SETUP AND RESULTS In this article we fabricated NIR OLEDs based on a new NIR organic dye ((4-((4-iodophenylimino) methyl) benzene-1, 3-diol) as an emissive layer by thermal evaporation technique. Usual structures of OLEDs are based on multi-layer organic small molecules sandwiched between two electrodes. They are made by sublimation of organic molecules in vacuum. To have a simple fabrication procedure, a single-layer OLED is made [16]. In this simple OLED structure, a light emitting layer which contains an organic material is inserted between two electrodes as shown in Fig 1. Application of a forward bias at the diode terminals causes carrier injection through the organic layers from the electrodes. These carriers move toward each other. Recombination of carriers from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO), produces photons with energy equal to the LUMO and HOMO difference. The released photons pass through the transparent electrode. Fig 1. Structure of a single layer OLED where the holes and electrons recombine in the organic (active) layer. Cathode is Mg and transparent anode is indium thin oxide (ITO) 978-1-4244-4873-9/09/$25.00 ©2009 IEEE Authorized licensed use limited to: Shiraz University. Downloaded on May 01,2010 at 08:09:19 UTC from IEEE Xplore. Restrictions apply.