Researchers at the Japanese Kanazawa University aim to improve the performance of perovskite solar cells by using two kinds of titanium oxide - anatase and brookite.
The team claims 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 reportedly helps 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 explained 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 compared different options like using anatase or brookite separately or various combination layers with anatase on top of brookite or vice-versa. They also highlighted how previous researchers had discovered that thin layers of titanium oxide are both transparent and able to transport electrons to the electrode.