Syntheses of benzotriazole based conjugated polymers for organic light emitting diode and organic solar cell

Önk, İpek
Nowadays, people are on the edge of huge energy problem since the concentrations of greenhouse gases are dramatically increased and it causes the greenhouse effect that lead to warming of the Earth. In order to lessen the effect, OLED devices gain importance since they help to decrease the energy consumption because of its low driving voltage. Therefore, the discovery of OLED ushered a new epoch for flat panel displays and solid state lighting. The most powerful candidate of green energy source is the solar energy because electricity is generated by using sun light. In this manner, polymer light emitting diode and organic solar cell (OSC) devices were constructed. In this study, benzotriazole based conjugated polymers containing selenophene as π bridges were coupled with fluorene and carbazole via Suzuki condensation reaction. The structures of polymers were verified with NMR and molecular weights of polymers were determined via GPC. OLEDs with an ITO/PEDOT:PSS/polymer/LiF/Al configuration was constructed by using newly synthesized polymers and orange color was observed. Luminance values were determined as 6608 cd/m2 for P1 and 2540 cd/m2 luminance for P2. Luminous efficiencies were 0.95 cd/A for P1 at 8.0 V and 0.27 cd/A for P2 at 9.5 V, respectively. Photovoltaic properties of P2 were investigated using ITO/PEDOT:PSS/P2:PC71BM/LiF/Al device configuration. The best performance of P2 based OSC device showed a Voc 0.86 V, a Jsc of 4.32 mA/cm2, a fill factor (FF) of 47.0 %, and a PCE of 1.75% under standard AM 1.5 G at 100 mW/cm2.