Spring Forward: Illuminating Advances in OLEDs and Solar Cells
/Spring is in the air, and with it, our focus on the transformative power of light in OLEDs and solar cells feels very relevant. Here is what you will find in our newsletter:
Top 3 Research Papers
Zhang, Y., Yang, Y., Li, G., et al. (2024). Joule, 8, 509.
https://doi.org/10.1016/j.joule.2023.12.009.
Organic solar cells (OSCs) are close to 20% efficient, and there are fewer concerns about their stability compared to perovskite PVs. A recent paper by Prof. Gang at The Hong Kong Polytechnic University in Joule demonstrates this.
Due to intermixed donor-acceptor domains, OSCs with a bulk heterojunction (BHJ) suffer from charge recombination. Layer-by-layer deposition (LBL) helps control the vertical distribution of the domains, leading to p-i-n junction formation and improved charge transport. Prof. Gang's group doubled down on LBL. They added the guest polymer PY-IT to enhance the vertical separation, resulting in a more pronounced p-i-n junction. The result is an OSC with higher mobility and balanced charge transport.
According to photo-CELIV measurements performed with the all-in-one platform PAIOS from FLUXiM AG, the mobility is two times higher with the PY-IT polymer compared to the reference. The best device had a certified efficiency of 19%, a record for LBL organic solar cells. The operational stability improved, as well. After 700h in ambient conditions at MPP, the device treated with PY-IT retained 96% of its initial performance, while the reference device dropped to 57%.
Identifying Performance Limiting Parameters in Perovskite Solar Cells Using Machine Learning
Zbinden, O., Knapp, E., & Tress, W. (2024). Sol. RRL, 8, 2300999.
https://doi.org/10.1002/solr.202300999
The trial-and-error approach is practical for finding what limits a low-efficiency perovskite solar cell. But it is material- and time-consuming. There is an alternative to this: Machine learning combined with drift-diffusion simulations.
Prof. Tress's research group developed a machine-learning model that identifies the parameters limiting the cell's efficiency. The model uses 11'150 simulated JV curves as training data and considers two methods to find the limiting parameters:
- Absolute method: this uses the absolute values of VOC, JSC, FF, and PCE. It is ideal for finding changes in the device structure.
- Difference method: this considers the difference between the measured parameters and the references extracted by the simulated JV curves. This helps identify the device properties that affect the PV working parameters.
This method is robust and helps you if:
- The solar cells fabricated with a standard recipe do not perform as expected.
- You ask yourself if a different fabrication recipe would lead to improved performance.
- You need to understand the solar cell's behaviour during degradation.
The training JV characteristics were simulated with Setfos.
The Blue Problem: OLED Stability and Degradation Mechanisms
Tankelevičiūtė, E., Samuel, I., & Zysman-Colman, E. (2024). J. Phys. Chem. Lett., 15(4), 1034.
https://pubs.acs.org/doi/10.1021/acs.jpclett.3c03317
Prof. Eli Zysman-Colman's team at the University of St. Andrews looks into understanding and addressing the challenges associated with blue OLEDs' stability and degradation mechanisms.
In this paper, they discuss recent progress in understanding device degradation pathways and provide an overview of possible strategies to increase device lifetimes without a significant efficiency trade-off. Only careful consideration of all variables that go into OLED development, from the choice of materials to a deep understanding of which degradation mechanisms need to be suppressed for the particular structure, can lead to a meaningful positive change toward commercializable blue devices.
Congratulations Dr. Andreas Schiller, Ph.D.
Our colleague Andreas Schiller has achieved a significant academic milestone by completing his Ph.D. at the ETH Zürich. Over the past six years, alongside this intense academic pursuit, he has admirably juggled multiple responsibilities: working at Fluxim and ZHAW as a Computational Scientist, embracing fatherhood not once but twice, and fulfilling his duties as a Company Commander in the Swiss military. On January 24, 2024, Andreas brilliantly defended his thesis titled "Transient and Frequency-Domain Simulation of Mixed Electronic-Ionic Charge Transport in Thin-Film Devices," a project partly sponsored by Fluxim. The insights from his research are set to enhance future versions of Setfos. Andreas has now started a full-time role as a Computational Scientist at Fluxim.
Congratulations, Dr. Schiller! What a balancing act, a feat which we’re sure many of our Ph.D. colleagues can relate to.
For a glimpse into his work, the abstract is available on the ETH website here. Although the full thesis is under a three-year embargo, we look forward to sharing excerpts from it in the future.
Fluxim welcomes Dr. Davide Moia to the R&D Team
The R&D Team at Fluxim has seen its project list expand rapidly over the past year, necessitating some reinforcements.
We are delighted to announce that Dr. Davide Moia has joined our team as an R&D Scientist, bringing his expertise to help us tackle our growing portfolio of innovative projects.
Davide brings a wealth of experience in the field of materials for solar energy conversion and storage. He comes to us from the Max-Planck Institute for Solid State Research in Stuttgart, Germany, where he has honed his expertise for over five years, most recently serving as Group Leader.
We look forward to a long and successful collaboration.
Welcome aboard, Davide!
Research Webinar 3: Optimizing Perovskite Quantum Dot LEDs
In our 3rd Research Webinar of 2024, we are delighted to welcome Dr. Sadhir Kumar from ETH Zürich who will be presenting his work from the Nature paper:
Overcoming intrinsic light outcoupling limit in perovskite quantum dots LEDs using low refractive index anisotropic nanocrystals
Date & Time: Tue, April 9, 10:00 - 11:00 AM (CET)
Dr. Sudhir will join Dr. Balthsar Blülle from Fluxim, who will present a talk on Angular luminescence spectroscopy to explore novel emitter and light conversion materials.
This webinar, hosted by Dr. Daniele Braga, will explore the theoretical and practical aspects of developing Quantum Dot LEDs.
This webinar is ideal for researchers, students, and professionals. It is a unique opportunity to enhance your understanding of OLEDs and QD LEDs and connect with leading experts.
*Prior Reading: Read the Open Access research paper here:
https://www.nature.com/articles/s41467-022-29812-5
We look forward to seeing you there.
Did you miss our last webinar on Perovskite Solar Cells? Watch it here.
On Wednesday, 13th March, we hosted the second in our new research webinar series. The event with invited speaker Dr. Sandeep Ravishankar from Forschungszentrum Jülich and Fluxim’s Dr. Sandra Jenatsch focused on Perovskite Solar Cells: Advanced Optoelectrical Characterizations & Simulations.
The webinar was a massive success, with over 380 registrants and 170 attendees. Thanks to all of you who attended. Given the difficulties with various time zones, we record the webinars and make them available to everyone. You can now watch the webinar here:
SimOEP’24 Submission Deadline: May, 31st
We invite you to the 9th International Conference on Simulation of Organic Electronics and Photovoltaics (SimOEP), to be held in Winterthur, Switzerland, from 2nd to 4th September 2024.
This conference highlights the progress and ongoing challenges in organic electronics, perovskite PVs, and LEDs. It brings together modelling experts and device physicists from industry and academia. The topics addressed include charge and heat transport, exciton dynamics, light propagation, and the simulation domain ranges from nanometers to centimeters.
📢 Key Highlights:
Hear insights from leading experts - The confirmed speaker’s list has just been updated.
Call for Abstracts: The submission deadline is 31st May, with acceptance notifications by 21st June.
Workshops & Exhibition: Featuring Fluxim's R&D tools like Setfos, Paios, and Litos Lite. Get a sneak peek at our future product prototypes and bring your devices for live demonstrations.
Registration Fees (3-Day Conference):
300 CHF for Ph.D. and Master students
400 CHF for professionals and scientists
(Conference dinner included)
📍 Venue: ZHAW School of Engineering, Technikumstrasse 9, Winterthur, CH (Physics Building - Room TP 406 & TP 408)
