Unique chalcogenide perovskites show promise for photovoltaics and LEDs

Scientists from the University at Buffalo have created thin films made from barium zirconium sulfide (BaZrS₃), a category of materials known as chalcogenide perovskites, and confirmed that it has impressive electronic and optical properties previously predicted by theorists.

The films reportedly combine exceptionally strong light absorption with good charge transport ' two qualities that make them ideal for applications such as photovoltaics and light-emitting diodes (LEDs).

In solar panels, for example, experimental results suggest that BaZrS₃ films would be much more efficient at converting sunlight into electricity than traditional silicon-based materials with identical thicknesses, says lead researcher Hao Zeng, PhD, professor of physics in the University at Buffalo College of Arts and Sciences. This could lower solar energy costs, especially because the new films performed admirably even when they had imperfections. (Manufacturing nearly flawless materials is typically more expensive, Zeng explains.)

In recent years, theorists have calculated that various chalcogenide perovskites should exhibit useful electronic and optical properties, and these predictions have captured the interest and imagination of experimentalists like Zeng.

The researchers crafted their BaZrS₃ films by using a laser to heat up and vaporize barium zirconium oxide. The vapor was deposited on a sapphire surface, forming a film, and then converted into the final material through a chemical reaction called sulfurization.

'Semiconductor research has traditionally been highly focused on conventional materials,' Hui says. 'This is an opportunity to explore something new. Chalcogenide perovskites share some similarities to the widely researched halide perovskites, but do not suffer from the toxicity and instability of the latter materials.'

'Now that we have a thin film made from BaZrS₃, we can study its fundamental properties and how it might be used in solar panels, LEDs, optical sensors and other applications,' Wei says.

In addition to the NSF and DOE SunShot program, the research received support from the National Natural Science Foundation of China and the U.S. National Nuclear Security Administration's Laboratory Directed Research & Development program.