Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV16)
Publication date: 28th March 2016
Research on the stability of organic and perovskite based solar cells is very important because the stability of a solar cell strongly affects how commercially viable the cell is. For a cell to be viable it needs to maintain its performance for a sufficiently long time to take advantage of reduced manufacturing costs or increased efficiency over other technologies. Raman and Photoluminescence (PL) spectroscopy are both powerful methods for probing the structural/chemical and photophysical/photochemical degradation as they are both quick and non destructive if performed with the correct parameters. While most studies use Raman and PL spectroscopy to probe thin films on a substrate the techniques can also be used to probe the degradation of the films in full devices. This information can then be used to assist in the design or the choice of materials in a device and help to increase stability. Here, micro-Raman and micro-PL spectroscopy, at the same device position, were applied to study the model type OPV devices with P3HT:PC60BM as the OPV layer. Our results show that the Raman peaks due to C-C and C=C vibrational modes drop in signal without any shift in position as the sample is increasingly degraded. The PL signal shows the same drop in signal as the sample is degraded. This study shows that the chemical degradation correlate well with the photophysical/photochemical degradation, and device degradation, showing the combination of Raman and PL spectroscopy on OPV devices can be a simple and fast approach to estimate the stability.