Optical innovations for solar modules - which are the most promising?
Symbolic picture with Microsoft Copilot.
In 2023, photovoltaic systems generated more than 5% of the world’s electrical energy and the installed capacity doubles every two to three years. Optical technologies can further increase the efficiency of solar modules and open up new applications, such as coloured solar modules for facades. Now, 27 experts provide a comprehensive overview of the state of research and assess the most promising innovations. The report, which is also of interest to stakeholders in funding and science management, was coordinated by HZB scientists Prof. Christiane Becker and Dr. Klaus Jäger.
Photovoltaics (PV) has become one of the most cost-effective technologies for generating electricity. In November 2024, the world’s photovoltaic systems reached an installed capacity of two terawatts, and the growth rates and cost reductions are still enormous.
Expertise from 22 research institutions
‘At a recent workshop, we discussed how the optics community can contribute to the further growth of photovoltaics,’ says Prof. Christiane Becker, head of the Solar Energy Optics Department at HZB. Christiane Becker and her colleague Dr. Klaus Jäger then invited international experts to compile a comprehensive overview of PV technologies and optical innovations. In total, 27 renowned experts from 22 research institutions in 9 countries contributed to the review.
Most promising concepts
The article begins with an overview of the current state of photovoltaics on a terawatt scale. From this, the experts identify issues and topics, where the optics community can contribute to enable large-scale deployment. ‘We have also identified a number of optical concepts that are currently only on the threshold of economic viability, but which hold the most promise for advancing PV technology,’ says Christiane Becker. These include optical innovations in the field of multi-junction solar cells, which have the highest efficiencies and therefore have great potential to further reduce the levelized cost of electricity.
Ecological aspects
Improved manufacturing processes using an eco-design approach and minimising the consumption of critical raw materials are also discussed. Another chapter is devoted to coloured solar modules as building integrated PV solutions. ‘Especially in cities, we need to use facades and other surfaces too for solar energy conversion, and of course, it does matter how the PV modules look. Such innovative solar modules allow sophisticated aesthetic solutions,’ says Becker.
Christiane Becker and Klaus Jäger are convinced that this comprehensive review does not only help the scientific community, but also decision makers in research funding.
- New method shows how molecular switches are influenced by their neighborsResearchers at Friedrich Schiller University Jena and the Helmholtz Centre Berlin (HZB) have, for the first time, been able to directly observe how the environment surrounding a molecular switch influences its electronic structure. Molecular switches are molecules that can be switched between two states by external influences such as changes in temperature—similar to a switch with the positions »On« and »Off«. Such molecules are being investigated as potential building blocks for future data storage devices or sensor materials. Using magnetic-field-dependent terahertz spectroscopy, the researchers have now, for the first time, been able to distinguish whether neighbouring molecules in a material are in the same or different states. The results have been published in the journal »Angewandte Chemie International Edition«.
- SEAlab accelerator project completed: Achievements and outlookThe SEAlab accelerator project successfully completed its final measurement campaign in summer 2026. The facility is now being dismantled, with many components set to be reused. The two accelerator physicists, Axel Neumann and Thorsten Kamps, explain what the project has achieved and provide an outlook for the future.
- BESSY II is back in operation after maintenance shutdownOn 7 September 2026, BESSY II was set into operation after a four-week shutdown. BESSY II is scheduled to resume full user operation on 22 September.