Center for Relativistic Laser Science

2017 120th KCS Meeting

Organic photovoltaic(OPV) is one of the most promising chemical components due to its potential to becoming next generation solar cell such as low cost, flexibility etc. Because of its potential, OPV has been studied to improve the power conversion efficiency. However, there is the Achilles heel of OPV, photodegradation. Even in the ambient condition, the stability of OPV is much lower than silicon based solar cell. In this research, we use our home-built Raman spectroscopy to observe the photodegradation process of PTB7-Th in molecular level. As a result, we found that during initial degradation process, two distinct phase are observed (Phase I, Phase II). In Phase I, oxygen is the crucial role in degradation. By using DFT calculation, we could find the place where the degradation occurs. In Phase II, water determines the rate of degradation. We hope this research would be the clue to find the valuable information during photodegradation.