MOSCOW, February 6. /TASS/ Scientists from Skoltech’s Institute of Problems of Chemical Physics, and Moscow State University have come up with inorganic perovskite solar batteries with tremendous efficiency, said Skoltech’s press service. The new devices exhibit very high efficiency in light conversion (10.5%) comparable with those of perovskite batteries based on classical hybrid materials (about 12%).

"Our devices demonstrate tremendous efficiency and excellent repeatability of electric characteristics from sample to sample," one of the study’s coauthors, Professor Pavel Troshin of the Center for Electrochemical Energy Storage said. "The obtained results demonstrate on the high potential of inorganic complex halogenides which offers new opportunities for target design of photoactive materials for effective and stable perovskite solar batteries."

What are perovskite solar batteries?

Perovskite is a mineral which is rare on the Earth surface, calcium titanate, while perovskites are various materials with crystal lattice similar to those of perovskite. In 2009, it was shown that perovskites are capable of effectively converting visual light into electricity, and ever since then they have been seen as a very prospective candidate for developing solar energy.

In 2013, Science, one of the world’s most reputable scientific journals, included perovskite-based solar batteries into the top 10 main breakthroughs of the year.

Batteries made from perovskites are cheaper than those based on silica and their production is non-toxic. These batteries can be made thin and flexible in order to place them on the surfaces of various curvatures.

Nowadays, the best efficiency of conversion light into electricity is achieved by hybrid perovskite photocells based on organic-inorganic materials APbI3 where A can be various organic cations (A=CH3NH2+ or HC(NH2)2+).

The performance coefficient of laboratory prototypes of such devices reaches 22% approaching the characteristics of photoelements based on crystalline silica. However, the commercialization of those setups is hindered by their poor service durability. Upon functioning, they deteriorate very fast due to thermal and photochemical decomposition of perovskites.

How one can substitute hybrid perovskite solar cells?

The most efficient approach to creating stable perovskite materials is a complete replacement of organic cations to inorganic ones. However, such substitution is normally accompanied by a decrease in the devices’ efficiency. For example, the solar cells based on CsPbI3 created by precipitation from the solution showed only 2-3% efficiency in light conversion.

In the new study, the Russian scientists suggested producing CsPbI3 using another technology - thermic co-evaporation of cesium and lead iodides. As a result, the solar batteries based on these inorganic perovskites have demonstrated a stable performance efficiency figure of about 10%. Herewith, the reference samples of solar cells with an analogous architecture based on coatings of hybrid perovskite CH3NH3PbI3 demonstrate a comparable efficiency of 10-12%.

The results of the study have been published in the Journal of Physical Chemistry Letters.