Scientists from the École Polytechnique Fédérale de Lausanne in Switzerland have recently developed low-cost perovskite solar panels that have 11.2 percent power-conversion efficiency and capable of operating for more than a year, without loss in performance.

The solar panel, described in a paper published in the journal Nature Communications, is a combination of 2D and 3D perovskite solar cell. Perovskite cells can mimic the structure of calcium titanate (CaTiO3) crystals. However, these kinds of solar cells have a range of light-capturing capacities depending on its elements.

Perovskite solar cells do not need any substantial quantities of expensive materials nor high-temperature processes, making it extremely cheap to produce. With over 22 percent power-conversion efficiency, perovskite cells have great potential for commercialization. However, there is still the issue on its operational stability. Earlier versions of perovskite cells can easily be degraded when exposed to water, ultraviolet light or even air.

In order to overcome its operational instability, the researchers thought of combining the qualities of 2D and 3D perovskite. The 3D perovskite cells are known for its ability to efficiently absorb light across the entire visible spectrum and transport electrical charges. On the other hand, the 2D perovskite cells are made from single layer of atoms and are more stable than the 3D ones.

Dubbed as the 2D/3D hybrid perovskite solar cell, the enhanced stability of 2D perovskite cells was mixed with the efficiency of 3D perovskite. Aside from protecting the 3D perovskite with a layer of 2D perovskite, the researchers also replaced the hole transporting materials with hydrophobic carbon electrodes. Due to this, the 2D/3D hybrid can be fully printed and operated under harsh conditions, without losing its performance.

The hybrid was able to produce 12.7 percent efficiency. When scaled up to 4x4-inch module, the product's efficiency slightly fall to 11.2 percent. Furthermore, the researchers were able to show that the 2D/3D hybrid perovskite solar cell can work for over 10,000 hours without experiencing any significant performance loss.