Will solar cells soon be made of perovskite?

What gives perovskite its promise is also what makes it difficult to master. The material has a hybrid structure in which inorganic and organic components come together.

“It’s what makes perovskite unique as a material, but also complex,” says Aslihan Babayigit, researcher at EnergyVille/UHasselt. “You do not just have electron transport. You also have ions moving through the material. So the system is constantly in motion, especially under the influence of light and temperature.”

Where conventional silicon cells behave in a relatively stable way, perovskites respond much more dynamically to their environment. That shows up in fluctuating performance and faster degradation.

“Perovskite cells perform very well at first, but they degrade under heat, moisture, oxygen, and UV light. That means they are currently not reliable enough for long-term use in solar cells.”At EnergyVille, that challenge is being tackled across the full value chain, from fundamental materials research to the development of working solar cells and modules.

From material to module and back again

Babayigit and her colleagues focus on the fundamental properties of the material, down to the nanoscale. In 2025, that approach led to an important breakthrough. The team investigated the interfaces between the different layers in a perovskite
solar cell, zones that are crucial for both performance and degradation.

“A perovskite cell consists of several ultra-thin layers, each with a specific function,” Babayigit explains. “It is often at the interfaces between those layers that defects or chemical changes arise that undermine stability. In other words, those interfaces are often the weakest links, but they are also very difficult to analyse.”

The team used advanced techniques such as TOFSIMS, which enables mapping the chemical composition layer by layer. In doing so, they ran into a fundamental problem.

“We saw that the measurement method itself can disturb the material,” Babayigit says. “The ion beam used for analysis can damage the interfaces, so you end up measuring artefacts rather than the material’s true behaviour.”

The team systematically documented those effects and developed an adapted measurement approach and protocol to avoid them. “In a field that is evolving this quickly, reproducibility is essential,” she says. “If you are not sure what you
are measuring, you keep building on the wrong assumptions.”

Uncovering a weak link

With their improved method, the team could identify an important degradation mechanism.
 “An interlayer that is often used today to boost efficiency turns out to detach under operational stress,” says Babayigit. “That means it is not stable in the long run, even if its initial performance is very good.”

That insight has direct implications for the further development of perovskite technology. “It means we need to rethink certain design choices,” she says. “But it also gives us a clear direction: we now know where we need to intervene.” At EnergyVille, that kind of insight can immediately be translated into practical advances. Fundamental materials research and the development of actual solar cells run in parallel.

“This is the kind of research you cannot do within a single discipline,” says Babayigit. “You need to understand what is happening at the nanoscale and be able to test it in real solar cells.”

Sustainable solar cells

Alongside stability, sustainability is another important issue when it comes to perovskite. Today’s highest-performing materials still contain lead, which raises questions about toxicity.

“That is definitely something we are mindful of,” says Babayigit. “But it is important to look at it in context. The quantities of lead are relatively limited and comparable to other applications, and there is a lot of work going into alternatives and better encapsulation to prevent leakage.”

That is why research at EnergyVille focuses not only on stability, but also on lead-free materials and safe integration into modules.

Moving closer to commercialisation

Conventional silicon solar cells are approaching their physical limit, with efficiencies of up to around 27% at cell level. Perovskites can break through that ceiling, especially when they are combined with silicon in so-called tandem cells. In those devices, different layers absorb different parts of the solar spectrum.

Perovskites are especially flexible in this respect, because their chemical composition can be tuned to absorb specific wavelengths. That makes it possible to use sunlight more efficiently than with a single material alone. 

“With that combination, we can reach efficiencies beyond what is possible today with silicon alone,” says Babayigit.

That brings the path to commercialisation another step closer.

Perovskite research at EnergyVille

At EnergyVille, perovskite technology is being studied across the full innovation chain:

• Fundamental insight into material behaviour and stability, including research into degradation mechanisms and long-term reliability.
• Development and optimisation of perovskite solar cells and modules: in 2025, a 28 x 28 cm² module achieved an efficiency of 20%, a world-leading result at that scale.
• In collaboration with Soltech, a first tandem module was developed, combining a perovskite top cell with a silicon cell.
  This demonstrator reached an efficiency of around 28% and shows the industrial potential of tandem technology.

Together, these research lines are bringing the commercialisation of perovskite technology a step closer.