A group of scientists at the National University of Singapore (NUS) have achieved a groundbreaking new record in the power conversation efficiency of solar cell technology.
The researchers at NUS attained this novel breakthrough power conversion efficiency of solar cells comprised of perovskite and organic materials. This sizable technological advancement clears the way for flexible, lightweight, economical and ultra-thin photovoltaic cells which are optimal for fuelling vehicles, boats, blinds and a variety of other applications.
The team’s results were published in the journal Nature Energy on 20 January 2022 and the research was carried out as part of a partnership with researchers from the University of Hong Kong and the Southern University of Science and Technology.
Solar cell technology for a green future
“Technologies for clean and renewable energy are extremely important for carbon reduction. Solar cells that directly convert solar energy into electricity are among the most promising clean energy technologies. High power conversion efficiency of solar cells is critical for generating more electrical power using a limited area and this, in turn, reduces the total cost of generating solar energy,” said lead researcher Presidential Young Professor Hou Yi, who is from the NUS Department of Chemical and Biomolecular Engineering.
Enhancing power conversion rates
“The main motivation of this study is to improve the power conversion efficiency of perovskite/organic tandem solar cells. In our latest work, we have demonstrated a power conversion efficiency of 23.6% – this is the best performance for this type of solar cells to date,” explained Dr Chen Wei, Research Fellow at the NUS Department of Chemical and Biomolecular Engineering and the first author of this work.
This accomplishment represents a massive jump forward from the present power conversion rate of around 20%, which has been recorded by previous studies on perovskite/organic tandem solar cells.
The new research is close to the power conversion rate of 26.7% of silicon solar cells, which is the leading solar cell technology in the current solar photovoltaic (PV) market.
Trends in solar technology
Solar cell technology has attained remarkable development in recent years as it presents a promising sustainable energy source. The consistency, productivity, resilience, and cost of solar cells has a major effect on the commercial potential and large-scale implementation of solar energy projects around the world.
Currently, the standard cells being used in solar power plants are centred on a single-junction architecture. The practical power conversion efficiency of single-junction solar cells is restricted to approximately 27% in industrial production.
In order to push the limits of solar energy manufacturing, innovative solutions are required for solar cells to perform better in power conversion.
To develop the power conversion efficiency of solar cells to more than 30%, stacks of two or more absorber layers (multi-junction cells) are necessary. Tandem solar cells, which are comprised of two varieties of photovoltaic materials, is a fast-developing area of research.
The NUS team’s novel discovery paves the way to thin-film tandem solar cells that are light and bendable, which may have a range of applications, including the potential for solar-powered blinds, vehicles, boats and other mobile devices.
Revolution in efficiency
A tandem solar cell consists of two or more subcells electrically attached through interconnecting layers (ICLs). The ICL performs a significant role in establishing the performance and duplicability of a device. An efficient ICL must be chemically inert, electrically conductive, and optically transparent.
While perovskite/organic tandem solar cells are promising for next-generation thin-film photovoltaics, their productivity falls short of other types of tandem solar cells. In order to overcome this technological challenge, Asstistant Professor Hou and his team created an efficient ICL that decreases voltage, optical and electrical losses within the tandem solar cell.
This advancement substantially enhances the productivity of the perovskite/organic tandem solar cells, achieving a power conversion rate of 23.6%.
“Our study shows the great potential of perovskite-based tandem solar cells for future commercial application of photovoltaic technology. Building on our new discovery, we hope to further improve the performance of our tandem solar cells and scale up this technology,” concluded Hou.
