Abstract
Organic light emitting diodes (OLED) based on solution processable poly[9,9-dioctylfluorenyl-2,7-diyl]-co-1,4-benzo-(2,1,3)-thiadiazole (F8BT) conjugated polymer active layer have been fabricated and characterized. Indium tin oxide, conducting polymer and aluminum were employed as an anode, hole injection layer and cathode respectively. Prior to diode fabrication, the surface morphology of polymer layers was thoroughly analyzed and their optical characterization was performed. The electrical properties of fabricated diodes with different active layer thicknesses have been studied by current-voltage method. The value of schottky barrier height, ideality factor and saturation current density was extracted according to the standard thermionic emission model. The influence of the individual emissive layer thicknesses on the current-voltage characteristics and luminous intensity of the OLED device was investigated. OLED devices exhibited a drop in turn-on voltage from 7.85 V to 3.58 V while reducing the thickness of emissive layer. Also the improved luminous intensity has been achieved by reducing the thickness with color coordinates of (0.42, 0.57).