STUDIES ON THE EFFECT OF LOW-INDEX LAYER BENEATH THE SUBSTRATE ON THE OUTPUT CHARACTERISTICS OF OLED

Abstract

For the past few years, organic materials have been extensively investigated as an electronic material for light emitting diodes. Organic materials offer strong promise in terms of properties, processing and cost effectiveness. LEDs developed from organic semiconductors as active layer are organic light emitting diodes (OLEDs). In an OLED various loss mechanisms occur during operation mechanism, which affects the efficiency of OLED. To improve the external quantum efficiency various methods are employed. One of these methods is insertion of low-index material between glass substrate and ITO layer. By insertion of low-index layer beneath the glass substrate helps in coupling out of substrate wave-guided modes trapped inside the device. But due to large mismatch between the refractive indices of low-index layer and iTO interface strong wave-guiding may occur in the Organic/ITO layers. As per the results of my simulations the insertion of low-index layer beneath the substrate decreases the transmission of the OLED device.