- Research reveals new type of back-contact solar cell design, using a perovskite material and tiny grooves embossed into plastic film, will enable scalable, low-cost manufacturing
- The elimination of expensive and scarce materials, such as indium, means the technology is both sustainable and affordable
- The lightweight, flexible solar films can be used on surfaces that could not normally stand the weight of solar panels creating broader accessibility to solar power, particularly in developing countries
- This could make a real difference in the global drive to replace fossil fuels with sustainable solar energy
Flexible solar cells that do not contain any rare earth metal are paving the way for the development of low cost, highly efficient solar energy according to new research by the University of Sheffield.
The research, which is in partnership with UK company Power Roll Ltd and published in ACS Applied Energy Materials, highlights the development of a new type of solar cell using a perovskite semiconductor. Unlike traditional solar cells, these cells are made by embossing tiny grooves into a plastic film and then filling them with the perovskite material.
This innovative approach presents a new way to produce lightweight, flexible solar films that can be used on surfaces such as rooftops and other unconventional surfaces that could not normally stand the weight of solar panels. Together with their anticipated low cost, this could significantly enhance the roll out of solar, particularly in developing countries.This could make a real difference in the drive to replace fossil fuels with sustainable solar energy.
The new microgroove structure creates a new type of solar cell that has a back-contact format. Regular devices use a sandwich structure composed of a number of layers deposited in a specific order. The back-contact cells have all the electrical contacts on the back of the device making it easier and cheaper to manufacture, with the potential for high efficiency.
To check the structure and composition of the solar cells a Hard X-ray nanoprobe microscope at Diamond Light Source in Oxfordshire, was used to take very detailed images of the solar cells. These also helped to spot hidden problems like empty spaces, flaws and the boundaries between tiny crystals within the semiconductor material. This was the first time this type of analysis had been used on this kind of solar cell.
The new technology also avoids the use of rare and expensive materials such as indium, making it cost-effective, scalable, and sustainable.
Professor David Lidzey, from the School of Mathematical and Physical Sciences at the University of Sheffield and co-author of the paper said: "A key advantage of these flexible films is that the panel can be stuck onto any surface. In the UK, you currently have to think twice about adding thick solar panels onto relatively fragile roofs of warehouses that are not really designed to be load-bearing. With this lightweight solar technology, you could essentially stick it anywhere. This could be a gamechanger for solar energy in low and middle income countries.
"Solar energy is a strategic priority for our research and one of our key competences is developing innovative techniques for fabricating and depositing solution-processable solar cells.
"We've partnered with Power Roll for over 10 years, combining our expertise in materials science and advanced imaging techniques with their focus on manufacturing and this collaboration has been very successful, resulting in this exciting new product."
The University of Sheffield is globally recognised as a leader in sustainability and advanced manufacturing. The University's dedication to tackling global energy challenges and commitment to renewable energy make it the ideal partner for Power Roll whose disruptive technology aims to shape global clean energy solutions via a secure and deployable product. In recent years, the two have worked together on multiple occasions to develop the technology needed to cultivate a brighter future for the UK.
Dr Nathan Hill, Research Scientist at Power Roll and lead author of the paper, said: "This partnership demonstrates the potential of combining cutting-edge research with industrial innovation to deliver transformative solutions in renewable energy. We are advancing technology that could play a significant role in achieving global net-zero targets, and by combining our collective research and academic capabilities we are able to further prove out the science sitting behind Power Roll's technology.
"It's exciting to see our relationship with the University of Sheffield continue to strengthen. Previously, we have worked with the University's Department of Physics and Astronomy to further develop our solar designs, which not only reduced manufacturing costs but also enhanced solar efficiency."
With perovskite solar generation still an emerging field, ongoing research and academic focus is greatly accelerating the advance of product development and scientific understanding. The next phase of the work on this project will be to further develop the use of X-ray microscopy in characterising these materials. New experiments are scheduled this summer, at the Diamond Light Source, to help understand key aspects of device operation, particularly device stability.
Dr Jessica Walker, I14 beamline scientist at Diamond Light Source Ltd. said: "The techniques and resolution offered by I14 are ideally suited to help answer scientific questions that remain around perovskite based solar cell materials. It is exciting to see how our capabilities have contributed to both academic and industrial research, and culminated in such a promising development for the field of energy materials, as well as a direct and tangible application with high potential for impact."
