In a significant advancement for solar energy technology, the transnational European research project “Bussard” has unveiled innovative approaches to enhance the efficiency of tunnel oxide passivating contact (TOPCon) solar cells. This research, led by Lorenz Andreas from the Fraunhofer Institute for Solar Energy Systems (ISE), aims to revolutionize the solar cell manufacturing process, with implications that could reshape the energy sector.
One of the standout achievements of the Bussard project is the implementation of atomic layer deposition (ALD) for creating aluminum oxide (Al2O3) passivation layers on the front side of TOPCon solar cells. This technique has been shown to significantly reduce the emitter saturation current density to an impressive 13 fA/cm², a critical factor in enhancing overall cell efficiency. “By employing ALD, we are not only improving the efficiency but also streamlining the production process, which is crucial for scaling up solar technology,” Andreas noted.
The project also introduced a novel fine-line metallization technique through multi-nozzle parallel dispensing, marking its first application in TOPCon solar cells. This method presents a promising alternative to traditional screen-printing, which has long been the standard in the industry. The results are compelling—TOPCon solar cells measuring 156.75 mm x 156.75 mm achieved a champion conversion efficiency of 24.2%, a figure independently verified by Fraunhofer ISE CalLab PVCells.
Another innovative aspect of the Bussard project is the evaluation of the Tape Solution interconnection concept for TOPCon cells and modules. This new approach has demonstrated feasibility in both small-scale and full-format modules, offering enhanced performance metrics. The research team conducted a thorough analysis of current-voltage (I-V) results and cell-to-module (CTM) losses using the SmartCalc® simulation tool. The findings reveal that the Tape Solution could outperform existing interconnection technologies such as SmartWire Connection Technology (SWCT) and electrically conductive adhesive (ECA).
The commercial implications of these advancements are profound. As the demand for efficient and cost-effective solar energy solutions continues to rise, the innovations stemming from Bussard could lead to a new generation of solar cells that not only promise higher efficiency but also lower production costs. This positions manufacturers to meet the growing energy needs sustainably, while also enhancing their competitiveness in a rapidly evolving market.
As the energy sector pivots towards renewable sources, the findings from this project, published in ‘EPJ Photovoltaics’ (European Physical Journal Photovoltaics), could serve as a catalyst for further research and development in solar technology. The potential for widespread adoption of these advanced solar cells could ultimately contribute to a greener future, aligning with global efforts to combat climate change and transition to sustainable energy sources.
