The NextBase project will realize the following 4 concrete objectives linked to the development of IBC-SHJ devices:
- Demonstrate IBC-SHJ solar cells with efficiency > 26.0%. This comprises:
- Production of highest quality wafers with lifetime over resistivity ratio > 2 ms/Ohmcm.
- Introduction of transparent front stack and advanced light management for Jsc > 42 mA/cm²
- Development of novel contact materials and contact designs for fill factor (FF) > 82% and Voc > 740 mV.
- Demonstrate IBC-SHJ solar modules with efficiency > 22.0%. This comprises:
- Development of 60-cell interconnection and anti-reflection coating (ARC) for cell-to-module (CTM) ratio > 95%.
- Implementation of encapsulation with relative power decrease <5% after degradation.
- Develop an industrial prototype plasma-enhanced chemical vapor deposition (PECVD) reactor for IBC-SHJ solar cells. This comprises:
- Production of 6-in wafer with lifetime > 2ms with patterned doped layer.
- Demonstration of minimum throughput of 10 wafers per hour.
- Develop processes that allow IBC-SHJ solar module cost of <0.35 euro per watt peak (€/Wp). This comprises:
- Development of high quality n-type wafers by low-cost multi-pulling process.
- Development of various cost competitive patterning and interconnection techniques.
The expected outcome of this project is to realize IBC-SHJ solar cells with efficiency above 26.0% and corresponding solar modules with efficiency above 22.0%. Practically, this means that the project is aiming to bring the silicon solar cell world record efficiency to Europe while employing simple process flow for this device type. This will also lead to an increase of the confidence of investors to re-invest in European PV companies and European PV technology. In particular, a number of new designs, new generations of materials and process innovations throughout the wafer, cell and module fabrication that go beyond the state-of-the-art will be introduced into the device to achieve the targeted efficiency values. Numerical simulations at device level and energy yield modeling at module level will additionally support the evaluation of the potential of the innovations brought into the IBC-SHJ device. The relatively large discrepancy between targeted cell and module efficiency is due to the stronger focus on the cell development targeting a new world record efficiency. Nevertheless, there is sufficient room for achieving IBC-SHJ module efficiencies well above 22.0% beyond the NextBase project. The very high efficiency of the IBC-SHJ technology, as long as the costs are not higher, is the key driver for cost reduction of IBC-SHJ based PV systems, since the increase of efficiency gives rise to the direct decrease of the levelized Cost of Electricity (LCOE). A LCOE close to 0.04€/kWh in the Sunbelt region can be expected based on the targeted module efficiency and cost.