Interest in renewable energy continues to grow as the world seeks to reduce its reliance on fossil fuels, and in relation to concerns about nuclear power. Wind and wave technologies remain one route; solar power (photovoltaics) is another.
With the new method, researchers from Northwestern University, Los Alamos National Laboratory and Rice University have come together to experiment with two-dimensional-layered perovskite. Perovskite is a calcium titanium oxide mineral composed of calcium titanate. This can form a type of crystal.
Tweaks to the production method have increased the stability of the crystal and have increased the power conversion efficiency three-fold. Reacting on social media, former White House energy consultant, Teryn Norris
(@TerynNorris) tweeted: “Berkeley Lab discovery could push solar PV perovskite cells to 31% efficiency.”
In a message to Digital Journal, lead researcher Hsinhan Tsai (Rice University) explains more about the properties of the crystal. “Crystal orientation has been a puzzle for more than two decades, and this is the first time we’ve been able to flip the crystal in the actual casting process.”
He then added how the efficiency had been enhanced: “This is our breakthrough, using our spin-casting technique to create layered crystals whose electrons flow vertically down the material without being blocked, mid layer, by organic cations.” In addition, vertically aligning the crystals also helps to boost their efficiency.
The stable two-dimensional crystal has been tested under constant lighting and in exposure to the air and found to keep its properties over a prolonged period of time. Tests were run alongside standard three-dimensional crystals, and the newly manufactured crystals showed superior performance, especially when ‘stress tested’ under variation with heat, humidity and light. This assessment was based on the photophysical properties of the crystals.
The new ultra-thin crystals also performed well when placed in the dark and then moved back into the light. This is known as recovery testing.
The research findings have been published in the journal Nature. The research is titled “High-efficiency Two-dimensional Ruddlesden-Popper Perovskite Solar Cells.”
