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37th European Photovoltaic Solar Energy Conference and Exhibition; 228-232, For the current PV production about 2000 tons of silver are consumed per year. This is already 10% of the entire world annual silver supply. The PV production is expected to grow significantly in the next decades in order to enable the energy transition to 100% renewables. Annual production volumes in the terawatt range are predicted already for 2030 and this may lead to higher silver price and put more pressure on the industry to replace silver by copper. With the currently available processes the cost advantage of copper plating over screen printing is relatively small and the implementation of plating in production is slowed down by the high up-front investment for equipment. The highest cost share of the process sequence has the patterning and research activities focus on new, i.e. more cost competitive patterning techniques. Within the Ameliz project several approaches are investigated: firstly, patterning by printing a metal seed grid with a dielectric layer as plating mask and secondly masking by a monolayer of self-assembling molecules. These molecules consist of a phosphonic acid group and a hydrocarbon chain. They are bonded to the ITO surface and form a monolayer of well-ordered, densely packed hydrophobic chains, which protects the ITO surface against plating solutions. Furthermore, methods for selective formation of a copper seed layer by electrografting and for improved adhesion by ITO reduction are being investigated.

37th European Photovoltaic Solar Energy Conference and Exhibition; 206-207, We present a firing-through metallisation approach for n-type passivating rear contacts that consist of a tunnelling oxide and an n-doped bilayer of a-SiOx and μc-Si. We find implied Voc up to 738 mV and contact resistivities as low as 20 mΩcm2. Implemented into 6-inch solar cells with a B-diffused emitter on the front, the best cell showed a Voc of 687 mV, FF 79.4 % and an overall efficiency of 22.2 %, proving the compatibility with metallisation by a conventional firing-through process. In view of the higher iVoc of the passivating μc-Si(n) contact, higher cell efficiencies are expected through improvements of the front side.

35th European Photovoltaic Solar Energy Conference and Exhibition; 229-232, The DISC project addresses the development of key technologies for the next generation of high-performance photovoltaic solar cells and modules. Our approach is to fully exploit the potential of silicon to its maximum by the use of passivating contacts or carrier selective contacts and junctions. Such contacts allow for simple, non-patterned double-side contacted device architecture and an enhancement of the energy yield, which will be key elements for achieving very low levelized costs of electricity. In this paper, selected highlights are presented concerning the first 18 months in the development of cell and module components such as In-free transparent conductive oxide layers with low sputtering damage. The synergies and results created within DISC will be also interesting for a drop-in combination with other solar cell and module technologies.