Projektbeschreibung
Entschlüsselung der Auswirkungen von Punktdefekten auf die Leistung von Metallhalogenid-Perowskiten
Metallhalogenid-Perowskite besitzen einzigartige Eigenschaften, die sie zur Verwendung in Solarzellenanwendungen geeignet machen. Die Forschung zu diesem Material hat dessen Effizienz bei der Umwandlung von Licht in elektrische Energie dramatisch um bis zu 25 % verbessert, sodass es mit modernen Solarzellen aus Silizium mithalten kann. Trotz seiner großartigen Eigenschaften kommt es bei dem Material zu Punktdefekten, die sich nachteilig auf seine Effizienz auszuwirken scheinen. Das EU-finanzierte Projekt OptElon wurde ins Leben gerufen, um diese kaum erforschten Defekte zu untersuchen. Die Forschungsgruppe wird das Einschwingverhalten von Geräten mit verschiedenen Perowskit-Materialien untersuchen, um den Ort und die Entwicklung des Defekts im Laufe der Zeit zu messen, die als Faktoren zu Rekombinationsverlusten in Solarzellen beitragen. Es ist zu erwarten, dass die Ergebnisse des Projekts signifikant zur Entwicklung effizienterer und zuverlässigerer Solarzellen und optoelektronischer Geräte beitragen werden.
Ziel
Defects in semiconductor materials commonly deteriorate the performance of optoelectronic devices such as solar cells and light-emitting diodes. In the recently emerged and highly successful hybrid metal halide perovskite, some lattice defects are even mobile leading to mixed ionic-electronic conductivity. This and other outstanding properties (tunable bandgap, lower dimensional embodiments, solution processability) make the perovskite a very interesting material for research and application. At the same time, it suffers from various degradation processes, linked to these poorly understood ionic defects. The major questions are: Where and what are these defects? How are they formed and how can we control their movement?
OptEIon will provide answers to these questions.
Based on my expertise in the device physics and experience in perovskites I will proceed as follows: First, I will characterize the transient response of devices with different perovskite materials, different stoichiometry, partial pressure of constituents, temperature, etc. to find clear evidence for the nature of the mobile defects and their diffusion constant. Second, I will employ nano-scale characterization on cross sections of working devices to measure location and time evolution of defects causing recombination losses in solar cells. In addition to established measurement techniques, I will use tip-enhanced (near field) spectroscopic techniques, which can provide super-resolution imaging. Third, I will apply device simulation to examine the measurement results. I will furthermore evaluate how machine learning in combination with our physical model could be implemented to help analyse device data. Fourth, I will exploit the results by fabricating demonstrator memristor arrays that can be controlled by light.
The outcome will be more efficient and stable solar cells and novel optoelectronic devices such as memristors, which are supposed to herald a new era of neuromorphic computing.
Wissenschaftliches Gebiet
- natural sciencesphysical scienceselectromagnetism and electronicsoptoelectronics
- natural sciencesphysical sciencesopticsmicroscopysuper resolution microscopy
- natural sciencesphysical scienceselectromagnetism and electronicssemiconductivity
- natural sciencescomputer and information sciencesartificial intelligencemachine learning
Schlüsselbegriffe
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-STG - Starting GrantGastgebende Einrichtung
8401 Winterthur
Schweiz