Improving hole transport layers in organic solar cells
| Reference number | |
| Coordinator | Linköpings universitet - Institutionen för teknik och naturvetenskap |
| Funding from Vinnova | SEK 232 804 |
| Project duration | November 2020 - September 2021 |
| Status | Completed |
| Venture | Research infrastructure - utilisation and collaboration |
| Call | Industrial pilot projects for utilisation of large-scale infrastructures for neutron and photon based techniques – 2020 |
| End-of-project report | 2020-03806_Epishine.pdf (pdf, 247 kB) |
Important results from the project
The project aimed to study organic mixed layers for use in Epishine AB´s organic solar cells. The aim was to map vertical molecular concentration gradients and how thermal stress influences the gradients. Furthermore, Epishine intended to study chemical changes in the organic mixed layer that occur with shorter and longer exposure to air. HIPPIE at MAX IV was used for the studies and both (thermal-stress-dependent) concentration gradients and air-induced chemical changes could be determined. The results were correlated with optical / electronic studies.
Expected long term effects
The results showed that molecular concentration gradients occur already at RT but change during thermal stress and even after long-term storage at RT. During short-term exposure to air, no detectable chemical changes occur, but with long-term exposure, new chemical bonds with oxygen can be detected. The results lead to further experiments to clarify possible changes in the electronic structure of the valence electron region and further development of the mixed layers.
Approach and implementation
The studies were performed at HIPPIE, MAX IV, and were supplemented with pre- and post-studies in the home laboratories (Epishine, LiU). The support for on-site experiments at HIPPIE was excellent and the beam line was well adapted for the studies. Problems with radiation damage could be handled by rastering the X-ray beam over the samples, but more sensitive studies of e.g. valence region electron structure are questionable. It would be desirable with "harder" X-rays, preferably in the "Tender" range. COVID-19 also hampered the project.