Posted: May 22nd, 2023

Fabricated to inspect the electroluminescent properties of SY PPV

For this conductive polymer we investigate its electroluminescent properties. As such, polymer light emitting diodes (PLEDs) combined with “structure of ITO (indium tin oxide)/PEDOT: PSS (poly (3, 4-ethylenedioxythiopene): poly (styrenesulfonate))/emission layer/ Ba/Al was fabricated to inspect the electroluminescent properties of SY PPV” (Mo et al. 1193). As it has been portrayed in the figure below (figure 1), the electroluminescence band of this conductive polymer exhibits a small red light shift relative to photoluminescence (PL) band. Moreover, the trend of EL assumes a bi-peak shoulder with the highest peak at 552 nm while the lowest peak coincides with the 528 nm mark. This behavior is a consequence of increased intensity of vibrations emanating from long wavelength bandwidth. Importantly, the CIE coordinates computed for the product obtained is found to be (0.388, 0.578) (Spiliopoulos 34). Figure 2 exhibits current density-luminance-voltage behavior of the polymer’s PLEDs. The turn-on voltage as exhibited by the graph shows that the luminance is triggered when the voltage is at 2.4V. The minimum luminance- 1 cd.m^-2 is what defines the turn-on voltage. From the trend, it can be seen that the optimum luminance of this SY PPV PLEDs exceeds 49000 cd.m^-2 and that it is achieved at a voltage of 8 V. This component has a peak LE of 21 cd.A^-1, and is equivalent to an 8% EQE. For this device, it is important to note that the presence of impurities greatly affect its performance. In this one though the effects of impurities were significantly minimized courtesy of the efficient synthesis method adopted (Hsieh 19). The influence of impurities on the EL efficiency is, however, a topic for another day.