Cost-effective, high-efficiency solar cells

Photovoltaic (PV) devices can now be seen on rooftops and solar farms across Europe, yet widespread implementation is hindered by costs and limits in efficiency. The EU-funded project 'Nanomaterials and nanotechnology for advanced photovoltaics' (NANOPV) addressed current bottlenecks in production with large-scale processes and equipment for production of PVs from nanomaterials.

The consortium studied a large variety of such materials, from zero-dimensional quantum dots, nanocrystals and nanoparticles to 1D nanowires and nanorods and even 2D ultra-thin nanolayers. In addition to materials' development to enhance efficiency, scientists developed cost-effective large-scale processes and equipment for integration into existing pilot and industrial production lines.

Nanomaterials can significantly enhance efficiencies by making better use of the electromagnetic spectrum, taking advantage of a broader range of available wavelengths. A more than 20 % increase in efficiency was targeted for wafer-based silicon devices and more than 15 % for thin-film silicon solar cells. Scientists also assessed low-cost solar cells entirely from nanomaterials.

Researchers demonstrated impressive efficiencies using transparent conducting oxide nanowires, silicon nanowires, and nanolayers with embedded nanoparticles of either silicon or indium. The team designed and fabricated solar cells based on the concepts.

Wafer-based silicon solar cells with efficiencies in excess of 20 % have been produced using industrial equipment. Scientists defined concepts for processing equipment chains for three of the most promising solar cell concepts.

The team set a cost target of well below EUR 1 per Watt peak, where one Watt peak is the maximum power output of a one-square-metre solar panel at 25 degrees Celsius. A technological platform was developed covering the complete fabrication process chain to fully exploit the technology with cost-effective and high-throughput production. NANOPV met its target cost thanks to cost-effective processing of nanomaterials.

NANOPV has contributed to development of a safe and cost-effective energy supply based on sustainable PV devices. Technologies will enhance the competitive position of the EU in a market poised for a major breakthrough.