Titanium oxide helps perovskite solar cell reach 16.8% efficiency

Scientists at Japan’s Kanazawa University are seeking to improve the performance of perovskite solar cells by using two special kinds of titanium oxide, anatase and brookite.

In particular, they claim to have reached a conversion efficiency of 16.82% in a perovskite cell by applying a brookite layer made of water-solute brookite nanoparticles on an anatase layer. This, according to them, enables to improve the transport of electrons from the center of the cell to its electrodes, while also preventing charges from recombining at the border between the perovskite material and the electron transport layer.

“Together, both these effects allow us to achieve higher solar cell efficiencies,” said the research coordinator, Md. Shahiduzzaman.

The research team stressed that the anatase layers were created by spraying solutions onto glass coated with a transparent electrode that was heated to 450 °C, while the brookite layers were produced with water-soluble brookite nanoparticles, as this kind of ink is more environmentally friendly than conventional inks.

The scientists have also made comparisons between different options as using anatase or brookite separately or combination layers with anatase on top of brookite or vice-versa. The also highlighted how previous researchers had discovered that thin layers of titanium oxide are both transparent and able to transport electrons to the electrode.

In January of this year, another group of Japanese researchers announced it used tin dioxide (SnO₂) instead of the more commonly used titanium dioxide for the production of a perovskite solar cell.

Earlier in March, a group of scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory showed the research results into the replacement of titanium dioxide in the manufacture of solar cells.

Scientists around the world have looked into substituting the lead in common perovskite designs with various materials, including titanium, tin and bismuth.