Welcome
To The GreenEnergyMaterials-Series
Our Mission
The Green Energy Materials Series (GEMS) aims to promote the work of emerging and established scientists in the field of renewable energy covering subjects such as photovoltaics, energy storage, green fuel production, and more!
With its seminar series, GEMS gives the stage to early career researchers and key players in the field to promote and discuss their work with a community of green energy enthusiasts. The series provides a platform for scientists to give feedback, hear about new trends, current challenges, and important techniques and insights.
This series aims to facilitate discussions and to enable deeper insights into phenomena and characterisation techniques. As such, presentations will focus on clearly defined topics covered in depth rather than a list of big achievements.
Presentations will be around 30 minutes long, with copious time for questions. The series will run online via Zoom once every month. Sessions usually start at 4.30pm Berlin time (GMT+1) but might vary depending on the speakers’ location.
With the speakers’ permission (an embargo period is possible), the talks will be recorded and uploaded to the GEMS YouTube channel.
We look forward to welcoming all of you to these events,
Vincent M. Le Corre | Simon Kahmann | Bowen Yang
Next Talks - 15 April 2026
Hebrew University of Jerusalem, IL
Identification of electronic processes at buried interfaces of optoelectronic materials is a long-standing challenge in materials science. These processes are crucial for understanding loss mechanisms in photovoltaic and photocatalysis research, where the devices comprise of at least three hetero-interfaces. Due to the experimental challenge in analyzing each of the individual interfaces in a sperate manner, the most common optoelectronic characterization is current-voltage sweep, done on a full device involving several buried interfaces, requires a transport model, and does not enable to separate the individual contribution of each of the interfaces. Thanks to its contactless nature, in recent years, time-resolved PL (tr-PL) is gaining popularity for the characterization of individual buried interfaces. Using tr-PL, many research groups utilize the measured tr-PL decays in order to try and extract information about charge extraction and non-radiative recombination losses. However, to-date, the interpretation of tr-PL decays for hetero-interfaces is still under debate in the community (and requires a kinetic model), and the exact loss mechanisms remain unresolved.
In this presentation, I will demonstrate how time-resolved Surface PhotoVoltage (tr-SPV) is a highly sensitive contactless method for optoelectronic characterization of individual buried interfaces, yielding valuable information about charge transfer, charge separation and non-radiative recombination mechanisms across different types of hetero-interfaces used in optoelectronic devices.
Starting from a single perovskite/hole transfer layer interface, I will show that tr-PL and tr-SPV provide complementary information on charge transfer kinetics and electron trapping/de-trapping mechanisms. Moving towards perovskite/silicon tandem solar cells, I will show how tr-SPV involving selective excitation of the individual top and bottom cells can yield valuable information on the charge transfer and recombination pathways at different buried interfaces, and enables to separate the contribution of each sub-cell, even when full device architectures are studied.
Sofiia Kosar
King Abdullah University of Science and Technology, KSA
Microscopic insights into the performance and stability challenges of perovskite solar cells
High performance and long-term stability of perovskite solar cells (PSCs) are essential for their transition to large-scale industrial production. However, device-level quality of PSCs is often dictated by microscopic inhomogeneities within the active perovskite layer. For example, local variations in composition, structure, and optoelectronic response can adversely affect both device performance and stability. Identifying and understanding these local inhomogeneities is critical for improving device operation. Given the complex composition and polycrystalline nature of perovskite materials, imaging techniques with high spatial resolutions are essential for identifying and characterizing such local variations.
In this talk, I will discuss how advanced imaging and spectroscopic techniques – ranging from ultraviolet photoemission to infrared scanning probe microscopies – can shed light on microscopic inhomogeneities. I will first discuss imaging of nanoscale defects with photoemission electron microscopy, highlighting the roles of these defects in performance and stability of PSCs. I will then discuss how scattering-type scanning near-field optical microscopy coupled with infrared light enables identification of nanoscale compositional impurities and will showcase the impact of these impurities on stability of PSCs.
These insights provide a deeper understanding of the detrimental roles of microscopic inhomogeneities in shaping the macroscopic behavior of PSCs, informing strategies to improve their operation.
In the Offing
15 April
Silvia Motti
Mare Dijkstra
Break
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