A Florida State University research team has addressed perovskite solar cells' stability issue by mixing the old with the new. Professor of Chemistry Biwu Ma and his team published a new study that shows if you add a layer of ancient organic pigment to a perovskite solar cell, it increases the stability and efficiency of the cell.

“Pigments are abundant, low cost and robust,” Ma said. “When we combine them with perovskites, we can generate new high-performance hybrid systems. It’s using the old with the new, and together they produce something really exciting.”

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

Adding the layer of insoluble pigment via facile solution processing and thermal annealing also makes the cell hydrophobic, meaning water cannot stay on the surface.

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