Blue organic light emitting diode (OLED) from two-layer structure of 4,4´-bis(2,2´diphenylvinil)-1,1´-biphenyl (DPVBi) and PVK

This paper reports the performance of blue color organic light emitting diode (OLED) that were fabricated using 4,4´-bis(2,2´diphenilvinil)-1,1´-biphenil (DPVBi) compound. The two-layer devices of the structure ITO/PVK/DPVBi/Al with variation of DPVBi thickness in the range of 20 nm to 65 nm were fabricated. Here the indium tin oxide (ITO) used as anode, poly-9-vinylcarbozole (PVK) as hole transporting layer, 4,4´-bis(2,2´diphenilvinil)-1,1´-biphenil (DPVBi) as the blue emitting layer and aluminum (Al) as the cathode. The DPVBi was prepared by thermal evaporation while the PVK film was prepared by spin coating technique. The performance of the device was analyzed through the current-voltage (IV) curve and the electroluminescence spectrum. The device with 56 nm DPVBi layer showed the optimum properties where its emitted light spectrum at peak of 483 nm and it turn-on voltage was 8.0 V.