Oct. 31 (UPI) -- Scientists have gained new insights into the properties of perovskites, the crystalline materials used to make solar cells. The breakthrough promises the development of more efficient, stronger and cheaper solar panels.
In the labs of McGill University in Canada, scientists used a special instrument called the multi-dimensional electronic spectrometer to observe the movements of electrons inside cesium lead iodide perovskite nanocrystals.
The instrument, designed by engineers at McGill, can track the behavior of electrons across extremely small timescales -- as short as 10 femtoseconds, or 10 millionths of a billionth of a second.
The observations made using the MDES instrument suggest the difference between liquids and solids isn't all that clear cut.
"Since childhood we have learned to discern solids from liquids based on intuition: we know solids have a fixed shape, whereas liquids take the shape of their container," lead researcher Hélène Seiler, a former doctoral student in McGill's chemistry department, said in a news release.
"But when we look at what the electrons in this material are actually doing in response to light, we see that they behave like they typically do in a liquid," said Seiler, now a researcher at the Fritz-Haber-Institut at the Max-Planck Institute. "Clearly, they are not in a liquid -- they are in a crystal -- but their response to light is really liquid-like."
The new research, published this week in the journal Nature Communications, allowed scientists to investigate the impacts of material defects on electron behavior in perovskites.
The findings suggest the material defects and liquid-solid duality in cesium lead iodide perovskite nanocrystals are essential to, not a hindrance of, the material's unique optoelectrical properties.
"It's the most exciting result that I have been a part of since starting in science in 1995," said senior author Patanjali Kambhampati, a chemistry professor at McGill. "Instead of searching for perfection in defect-free silicon microelectronics, here we have a defective thing that's defect-tolerant. And now we know a bit more about why that is."
Scientists expect further exploration of the material's defects and duality will help engineers design more effective perovskite materials, inspiring better, cheaper solar cells.