The chemistry professor uses old materials to create newer and better solar cells

A Florida State University research team is mixing the old with the new to create a more stable solar cell.

Chemistry professor Biwu Ma and his team have published a new study showing that adding a layer of ancient organic pigment to a perovskite solar cell increases the cell’s stability and efficiency.

The study is published in the journal Applied chemistry .

“The pigments are abundant, low-cost, and robust,” said Ma. “When we combine them with perovskites, we can generate new, high-performance hybrid systems. Use the old with the new and together they produce something truly exciting.”

Ma’s research in next-generation solar cell technologies has focused on addressing the stability issues and challenges of perovskite solar cells. A perovskite solar cell is a type of photovoltaic cell that includes a structured perovskite compound, most commonly a hybrid material based on organic-inorganic lead or tin halide, as a light-collecting layer.

Over the past decade, research into perovskite solar cells has exploded. When they were first reported in 2009, the power conversion efficiency stood at around 4%, which now reaches 25%. However, there are drawbacks to commercial viability, such as the material’s tendency to degrade rapidly.

Researchers around the world have been looking for that perfect formula to make them both stable and highly efficient.

The solar cell that Ma’s team used for the experiment, based on lead iodide and methylammonium, had an efficiency of 18.9% without the pigment layer. With it, that number went up to 21.1%. The team also found that with the addition of the pigment layer, the cell without encapsulation could maintain 90% of its initial efficiency after 1,000 hours under ambient conditions.

Adding the insoluble pigment layer via easy solution processing and thermal annealing also makes the cell hydrophobic, which means that water cannot remain on the surface.

“We believe surface passivation of these cells using low-cost pigments is a very promising approach to improve their stability and efficiency,” said Ma.