Best practice Improving solar cells using nanostructures

Improving the efficiency of solar cells while at the same time reducing the costs: that’s the mission of Piero Spinelli (postdoc) and Claire van Lare (PhD student) at AMOLF. Using high-resolution simulation, they can calculate the optimal arrangement of nanoparticles on a solar cell.

Zonnepanelen in een veld

Nanophotonics

Spinelli and Van Lare are both part of the group led by Albert Polman, whose research focuses on nanophotonics: the control, understanding and application of light at the nanoscale. “Our work consists of experiments, on the one hand, and theory and simulations, on the other”, explains Spinelli. “We do both. Here at AMOLF we use nanofabrication to add nanoparticles to solar cells. But we also want to understand the physics behind it and learn more about capturing light in solar cells. For that we need simulation, and for simulation we use the Lisa compute cluster at SURFsara.”

How to capture light

The challenge Spinelli and Van Lare are working on is to find ways to trap light in a solar cell. Van Lare: “To reduce costs, we want to make the solar cells very thin. But when you make a cell thin, it absorbs less light, since the light passes through. That’s why we add nanoparticles: they scatter the light and allow us to capture light inside the cell.”

“We need the compute cluster Lisa at SURFsara for these extensive simulations as they exceed the capacity of our own systems in both memory and computing power.”

Optimal arrangement

Simulation helps to find the optimal geometry for nanoparticles, explains Spinelli. “We can change their size or the way they are arranged on top of the cell. Once we’ve established the best pattern, we create the cell. ” The simulations have a 3D structure that includes all the layers used in a real solar cell, says Van Lare. “We add the nanoparticles and we simulate what will happen to the light when it enters a cell. We need the compute cluster Lisa at SURFsara for these extensive simulations as they exceed the capacity of our own systems in both memory and computing power.”

More efficiency, lower costs

According to Spinelli, the results so far are promising. “By using the optimal arrangement of nanoparticles, we can improve the efficiency of an existing solar cell by a few percent, say from 20% to 22%. It may not sound like much, but in the world of solar cells that’s a lot.” However, it’s not only about efficiency. “Our research allows us to develop solar cells that are much thinner, since the light can be trapped inside”, says Van Lare. “These cells contain less material and are therefore cheaper, while retaining the same efficiency.”