Hybrid organic-inorganic perovskite-based solar cells have emerged as a very promising photovoltaic technology. Since its introduction in 2009, the power conversion efficiency (PCE) has gone from 3.8% to 25.2% nowadays. Besides high efficiencies, perovskite solar cells (PSCs) have the possibility to become a very cheap technology, due to the use of abundant and cheap materials and due to simple solution-based processing at low temperatures. As the perovskite material yields a high absorption coefficient, only a few hundreds of nm thickness is enough to absorb more than 90% of the incoming visible light, making PSCs part of the thin film photovoltaics. Consequently, PSCs can be processed on flexible substrates, introducing a wide variety of possible applications.
Despite the high efficiencies, some obstacles have to be overcome in order to commercialize these solar cells. One issue is the scalability, which is the consequence of the simple, solution-based processing. It is very challenging to transfer the high efficiencies to larger substrates. The second issue, the scope of this work, is the stability. Perovskite is a sensitive material, as it easily degrades upon exposure to UV-light, high temperatures, oxygen, humidity, ... (outdoor conditions). Many improvements have been made in the last years by changing the perovskite composition (perovskite is a lab-made material after all) and changing the materials used for the selective contacts and electrodes. Nevertheless, further improvement is required in order to both push the efficiencies even higher and improve the stability.
In this work, the student will focus on the perovskite layer and its interfaces with the selective contacts. The goal is to improve the stability by using additives in the processing of the perovskite layers and by introducing interfacial layers (sub-nanometer thickness). The influence of these measures on the performance will be characterized through JV curves, EQE and absorption measurements. The influence on the crystal quality will be characterized mainly by (X-)SEM and XRD (with the possibility of FTPS and DLTS depending on the results). Finally, the influence on the stability will be characterized by monitoring the performance after or while stressing the PSCs (high temperatures, light soaking, ...).
The work will be conducted in the newly built laboratories at imec in EnergyVille, Genk.
Type of Project: Thesis; Combination of internship and thesis
Duration: 6-9 months
Required degree: Master of Engineering Science
Required background: Chemistry/Chemical Engineering; Energy; Materials Engineering; Nanoscience & Nanotechnology; Physics
Supervising scientist: For further information or for application, please contact Stijn Lammar (email@example.com).
Only for self-supporting students