Researchers have developed a novel passivation technique for perovskite-silicon tandem solar cells, reaching record efficiencies and paving the way for more advanced solar technology.

An international team of photovoltaics researchers has made a significant step toward large-scale industrial use of perovskite-silicon tandem solar cells. They demonstrated that the perovskite top cell can be effectively passivated when paired with textured silicon bottom cells featuring the large pyramidal structures common in today’s solar industry.

Their findings also show that passivation affects the entire perovskite layer, unlike in silicon cells where surface treatments only impact the uppermost layers, resulting in additional efficiency gains. Researchers from King Abdullah University of Science and Technology (KAUST), the University of Freiburg, and the Fraunhofer Institute for Solar Energy Systems ISE outlined these advancements in developing passivated perovskite top cells.

Figure 1. Perovskite-Silicon Tandem Solar Cell by Researchers

Perovskite-silicon tandem solar cells pair a perovskite top cell with a silicon bottom cell, marking the next major advance in photovoltaic technology. This approach is especially important as conventional silicon solar cells approach their theoretical efficiency limit of 29.4% for sunlight-to-electricity conversion. Figure 1 shows Perovskite-Silicon Tandem Solar Cell by Researchers.

For large-scale production of tandem solar cells, using standard silicon bottom cells is advantageous because their manufacturing processes are well established. These silicon cells are textured to increase surface area and boost efficiency, but this texturization makes it challenging to deposit the perovskite layer. Until now, achieving high-quality surface passivation of the perovskite top cell on the pyramid-like texture had not been accomplished.

Breakthrough Technique

“Until now, effective passivation on textured perovskite-silicon tandem solar cells had been limited, mostly working only on flat-front architectures. We have now achieved excellent passivation by applying 1,3-diaminopropane dihydroiodide to the uneven perovskite surface,” said Dr. Oussama Er-Raji, lead author and scientist at Fraunhofer ISE. The passivated tandem cells reached a conversion efficiency of 33.1% with an open-circuit voltage of 2.01 volts.

The researchers also found that passivating the perovskite top cell enhanced its conductivity and improved the fill factor. This effect arises from a deep field generated by the passivation. Unlike silicon solar cells, where passivation affects only the surface, in perovskite cells the treatment influences the entire absorber layer, boosting its bulk properties.

Laying the Groundwork for Future Studies

“This breakthrough provides a strong foundation for future research in this field,” said Prof. Stefaan De Wolf, KAUST, noting that it deepens understanding of the top cell’s light-to-electricity processes and helps guide the development of improved tandem solar cells.

“Surface passivation isn’t just a desirable feature—it’s essential for boosting efficiency and stability,” added Prof. Stefan Glunz, University of Freiburg and Fraunhofer ISE. “Just as passivation was key to achieving high efficiencies in industrial silicon solar cells, these advances will similarly benefit the photovoltaic industry for perovskite-silicon tandem cells.”

References:

1. https://scitechdaily.com/perovskite-silicon-tandem-solar-cells-achieve-record-breaking-33-1-efficiency/

Cite this article:

Janani R (2025), Perovskite-Silicon Tandem Solar Cells Hit 33.1% Efficiency, AnaTechMaz, pp. 279