رسائل ماجيستير
English
2020
Enhancing the Photo-oxidative Stability of Non-Fullerene Electron Acceptors
ايان ماكولوتش, سلمان الشريف
جامعة الملك عبدالله للعلوم والتقنية · السعودية
Even though improvements in the efficiency of organic solar cells encouraged thecommercialization of this technology in the past two decades, the stability of organic solarcells is still an active area of research. The effect of photo-oxidative degradation on theperformance of organic solar cell devices is significant. One way to lower the rate of photooxidationdegradation is by preventing oxygen molecules from reaching the active layer oforganic solar cells. This could be achieved by fabricating the devices in an inertenvironment in the absence of oxygen. Once the devices are fabricated, they would been capsulated in a transparent material.1, 2 Even though this is a viable solution, there aretwo main issues. First, it was shown that oxygen molecules could diffuse through theencapsulating material and degrade the devices.3 Second, implementing this solution wouldincrease the fabrication cost of these devices, which would make this solutioncommercially unfeasible compared to other solar cell technologies.3 Speller and hiscolleges reported a possible mechanism of the photo-oxidative degradation and showed arelationship between the rate of degradation and LUMO energy levels of electron acceptormolecule4. In this thesis, we report the photo-oxidative degradation rate of O-IDTBR andO-IDTBR-(C3N2)2. The later electron acceptor is analogous to O-IDTBR with deeperLUMO by 0.1 eV. After four hours of constant irradiation from a 1-sun intensity xenonsolar simulator, the maximum UV-Vis absorbance of O-IDTBR is reduced by 12% relativeto O-IDTBR-(C3N2)2. Lower absolute degradation rates were observed when 1-sun LEDsolar simulator was used compare to xenon solar simulator.
