The secret of the most stable and efficient perovskite solar cells

Research unravels the operation of the most efficient and stable perovskite solar cells.

Perovskite-type solar cells (named after the mineral with the same name, which reproduce some key characteristics) could be the alternative to currently marketed crystalline silicon, as they present advantages over conventional silicon solar panels, such as a higher efficiency (efficiencies greater than 25%) and lower cost.

Perovskite cells are made by “solution processing” which is cheaper and less polluting than purification of silicon.

The main drawback of perovskite solar cells when it comes to commercialization is their stability, and it is in this area that scientific research on said solar cells is currently concentrated.

Researchers led by Henry Snaith and Elisabeth A. Duijnstee (Oxford University, United Kingdom) and Juan Luis Delgado (Ikerbasque, POLYMAT and the University of the Basque Country (UPV/EHU), Spain) have joined forces to obtain revealing information about the use of latest generation additives aimed at achieving high efficiency and high stability solar cells.

A perovskite type solar cell. (Photo: Dennis Schroeder/National Renewable Energy Laboratory)

In recent years, several research groups have described highly efficient perovskite solar cells by incorporating a small amount of additive (methylenediammonium dichloride) to achieve the highest certified efficiency so far for perovskite solar cells (25.7% PCE ).

The authors of the new study have investigated the role of the additive during the growth of perovskite crystals and have found that this additive decomposes over time giving rise to more stable chemical forms that confer an improved stability to the perovskite (more than 1 year exposed to air).

These results are extremely important and will have direct consequences for the future development of stable and high-efficiency perovskite photovoltaic devices.

The study is titled “Understanding the Degradation of Methylenediammonium and Its Role in Phase-Stabilizing Formamidinium Lead Triiodide”. And it has been published in the Journal of the American Chemical Society. (Source: UPV/EHU)