Workgroup Emerging solar cell technologies
Prof. Dr. Robby Peibst
Tel.: +49(0)5151-999 313
Back-contact solar cell with passivating p+ and n+ poly-Si on oxide (POLO) contacts, achieving an efficiency of 26.1%.
Bifacial PERT solar cell with ionimplanted p+ and n+ regions.
Mask alignment for photolithography.
The „Emerging solar cell technologies“ group evaluates new c-Si solar cell concepts and process technologies, covering fundamental questions as well as industrial applications. Our aim is to reduce the cost of energy generation by increasing the energy output and to develop innovative unique selling points for our industry partners (material suppliers, equipment manufacturers, solar cell producers). A characteristic of the work is the timeframe of 3 to 5 years for expected market introduction. The current main focus of the group is passivating contacts based on doped polycrystalline silicon layers that are deposited on thin passivating interface oxides (POLO, poly-Si on oxide).
The activities within the group can be broken down into the following strongly inter-related research areas:
Fundamental investigations of passivating contacts and transparent conductive oxides (TCOs) and their conceptual further development
- Electrical characterization of passivating contacts with regard to current transport and recombination behavior
- Optical characterization of passivating contacts and TCOs, in particular with regard to parasitic absorption, and evaluation of approaches to increase transparency
- Structural characterization of passivating contacts, in particular with regard to local disruptions of the passivating interface oxide
- Modeling of current transport through passivating contacts based on experimentally determined input parameters in order to optimize their performance
Integration of passivating contacts into highest-efficiency solar cells to demonstrate their efficiency potential
- Development and optimization of different methods to form passivating contacts (different interfacial oxides, different techniques to deposit Si)
- Evaluation of different solar cell concepts (contacts on both sides or only one side, one or both polarities formed by passivating contacts)
- Development of lean process sequences that differ as little as possible from current state-of-the-art processes and utilize existing manufacturing equipment
- Utilization of passivating contacts as an interconnection between bottom and top cell in monolithic tandem configurations
Evaluation of innovative module interconnection concepts (in collaboration with the “Modules” group)
- For example: Flip-flop interconnection of front-side to front-side or rear-side to rear-side, made possible by bifaciality factors >99%
The group also offers services in the abovementioned fields
- For example: evaluation of wafer quality or other individual components on highest-efficiency solar cells