Crystalline silicon (c-Si) photovoltaics is the dominant technology today for solar power generation. However, the cost-efficient production of c-Si solar cells is approaching its limits. Recently, multi-junction solar cells employing perovskite and c-Si solar cells have shown to bear the exciting potential to surpass the efficiency limit of market-leading single-junction c-Si solar cells. Monolithically integrated or mechanically stacked perovskite-Si multijunction tandems approaching or even surpassing 25% power conversion efficiency have been reported, though typically on small area devices (<1cm²). Scaling up this technology and maintaining high efficiency over large areas is crucial for the economic viability of such perovskite-based multi-junction technology.
Different perovskite-Si multijunction configurations can be considered, each of them having its specific optical and electrical requirements and benefits. The monolithic two-terminal (2T) stack operates with a highly transparent front electrode and an effective intermediate contact but relies on optimal current matching to maximize its output power. The mechanical four-terminal (4T) stack is not bound to this current matching requirement but needs both a highly transparent top and middle electrode. The three-terminal (3T) approach can act as a go-between loosening the requirements on the middle electrode while enabling to actively manage the current matching issue. The object of this study is to quantify the optical and electrical requirements and the overall potential of these multijunction configurations, based on actual fabrication and characterization of each of the concepts. Compatibility with industrially scalable fabrication techniques as well as balance-of-system requirements for module integration are to be taken into account, thus enabling the future deployment of high-performance large-area perovskite-based multi-junction solar modules.
Imec has a strong background in perovskite solar technology and its upscaling to larger area modules. Based on this, we’re already frontrunner in large area 4T perovskite-Si multijunction fabrication. https://www.imec-int.com/en/articles/imec-reports-record-conversion-efficiency-of-23-9-percent-on-a-4cm2-perovskite-silicon-solar-module
Embedded in this strong team, you will be able to rely on this background, complemented with support on optical modeling, Si solar cell technology options for the bottom cell, and extensive characterization techniques.
Required background: nanotechnology, semiconductor physics, materials science, materials engineering or electrical engineering
Type of work: 50% experimental work, 20% literature and technology study, 15% modeling and data analysis, 15% reporting (e.g. publications)
Supervisor: Jef Poortmans
Daily advisor: Tom Aernouts
The reference code for this PhD position is SE1712-19. Mention this reference code on your application form.