Hybrid organic-inorganic perovskite-based solar cells have reached in recent years cell efficiency values rivalling those of established thin-film photovoltaic technology (CIGS, CdTe), even approaching crystalline Si (c-Si) records.
Reproducibility of these record results, as well as maintaining the efficiency at high value during operation or under external stress (humidity, oxygen, temperature ...) has not been proven to a level that can guarantee economical viability. Therefore, harnessing the full potential of this new materials class for photovoltaic power generation requires a more in-depth understanding of the device physics determining the operation and stability of these solar cells.
You will perform opto-electronic characterization (photo- and electro-luminescence, impedance spectroscopy ...) on perovskite solar cells, with variations in perovskite crystal structure, contact layers and electrodes. You will determine the parameters relevant for setting up an equivalent circuit describing the device and the impact of these parameters on potential improvements in power conversion efficiency and performance stability.
Based on these findings and in collaboration with the team, (metal-oxide) interface layers, (halide-based) processing additives or other crystal growth controlling compounds will be introduced to remediate surface or grain-boundary recombination to result in higher performance (through e.g. improved Voc), reproducibility (controlled crystal growth) and stability (grain boundary passivation or confinement).
Ultimately, accelerated lifetime tests (ALTs) by stressing the devices under e.g. high intensity illumination and elevated temperature will be conducted to extract degradation factors and correlate these with the device operation physics. Extrapolation of device lifetimes under real-life conditions based on the findings of these accelerated tests will be coupled with actual outdoor tests.
Imec is part of the global effort to understand this hybrid organic-inorganic perovskite technology and develop stable high performing solar cells. We have successfully developed protocols for the production of +19% efficient solar cells and hold record efficiencies at module sizes up to 15x15 cm².
Required background: nanotechnology, semiconductor physics, materials science, materials engineering or electrical engineering
Type of work: 50% experimental work, 20% data analysis and modeling, 15% literature and technology study, 15% reporting (e.g. publications)
Supervisor: Jef Poortmans
Daily advisor: Tom Aernouts
The reference code for this PhD position is SE1712-15. Mention this reference code on your application form.