New lead-free perovskite material for solar cells

A class of materials called perovskites has emerged as a promising alternative to silicon for making inexpensive and efficient solar cells. But for all their promise, perovskites are not without their downsides. Most contain lead, which is highly toxic, and include organic materials that are not particularly stable when exposed to the environment.

Now a group of researchers at Brown University and University of Nebraska – Lincoln (UNL) has come up with a new titanium-based material for making lead-free, inorganic perovskite solar cells. In a paper published in the journal Joule (a new energy-focused sister journal to Cell), the researchers show that the material can be a good candidate, especially for making tandem solar cells — arrangements in which a perovskite cells are placed on top of silicon or another established material to boost the overall efficiency.

The research showed the material has several advantages over other lead-free perovskite alternatives. One contender for a lead-free perovskite is a material made largely from tin, which rusts easily when exposed to the environment. Titanium, on the hand, is rust-resistant. The titanium-perovskite also has an open-circuit voltage — a measure of the total voltage available from a solar cell — of over one volt. Other lead-free perovskites generally produce voltage smaller than 0.6 volts.

Read more at Brown University

Image Credit: Brown University

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