Scientists in Sweden and China developed a solution-based process to produce organic solar cells, demonstrating efficiencies better than 17%. The process utilizes paraxylene as a solvent, which the researchers claim is less toxic and more stable than others used to reach high organic solar cell efficiencies, and with more work could be scaled up to produce large area devices.

Scientists in the UK delved deep into the structure of a perovskite solar cell, looking to understand the complex relationship between the materials that make up the perovskite layer, and the role of different defects in both limiting and improving performance. The findings could allow for new perovskite materials that are specially structured to maximize PV performance.

Scientists in the United States pieced together data from hundreds of different sources, looking to establish the key factors that have led to consistently falling prices for lithium-ion technology since their commercialization thirty years ago. They find that public-funded research, primarily in chemistry and materials science, has made the largest contribution to cost reduction. And they offer suggestions on policy and investment to ensure that the research can continue to make these important contributions to reduction in battery costs.

In an update to its annual International Technology Roadmap for Photovoltaics, German engineering association VDMA discusses the readiness level for various technologies in PV cell and module manufacturing, finding that more process development is needed for 210mm wafers – the largest format currently on the market – to match the throughputs that will soon be achievable with smaller formats including 182mm.

Scientists at Germany’s Fraunhofer Insititute for Solar Energy Systems (ISE) evaluated the performance of its newly introduced ‘Matrix’ approach to interconnecting shingled solar cells. The institute finds that, thanks to optimized current flows, energy yield of the Matrix approach could almost double that of standard shingled cell interconnection under random shading conditions.

Scientists in Germany analyzed the main sources of performance loss in a silicon heterojunction cell, and developed several optimization strategies to improve overall performance. By adding a second layer of amorphous silicon at the rear of the device, and a magnesium fluoride anti-reflective layer, they were able to boost cell efficiency by around 1% to reach 24.51%.

Scientists in Japan and Europe investigated the long-term stability of perovskite solar cells utilizing layers of mesoporous carbon, building on previous work demonstrating the strong potential of this approach. This latest work demonstrates a light-soaking effect, which allowed them to fabricate cells that retained 92% of their initial performance after 3,000 hours in damp heat conditions – which the researchers say is equivalent to 20 years in the field.

Scientists in the United States investigated adding a layer of copper-aluminum oxide to the rear side of a cadmium-telluride thin film cell, finding positive impacts on carrier lifetime and efficiency. With further work, the scientists say, the discovery could open up new routes to higher efficiencies in CdTe solar cells.

Scientists in Korea evaluated recent progress in the development of low cost, large scale processes for the production of perovskite solar cells on flexible substrates, finding that several challenges remain. The group recommends that research should focus on developing novel processes and materials for perovskite solar cell production, rather than adapting those already in use elsewhere.

An international team of scientists trialled a new approach to passivating defects in perovskite solar cells. Using a tailored arrangement of atoms, the team was able to overcome challenges related to the formation of a two-dimensional perovskite layer on top of the active cell material, and reach 21.4% conversion efficiency for a 26cm² active area, which they claim as a record for a perovskite device of this size.