Developed by Ted Sargent, a professor at the University’s Edward S. Rogers Sr. Department of Electrical and Computer Engineering, and Zhijun Ning, a post-doctoral researcher, the new form of nanoparticle, called colloidal quantum dots (CQDs), depends on two semiconductors that include n- and p-type.
The new CQD n-type semiconductors bind to oxygen atoms when exposed to air, which damages their electrons and turns them into p-types.
The research team achieved 8% solar power conversion efficiency, which they claim is the best result reported to date.
Ning said, "This is a material innovation, that’s the first part, and with this new material we can build new device structures."
"Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stability — no one has shown that before," Ning added.
The researchers said the work may lead to inks that could be painted or printed onto thin, flexible surfaces to create low-cost solar power products, such as roofing shingles.
Sargent said the field of colloidal quantum dot photovoltaics needs continued improvement in absolute performance, or power conversion efficiency.
"The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels," Sargent added.
Image: Co-authors Zhijun Ning (left) and Oleksandr Voznyy (right) examine a film coated with colloidal quantum dots. Photo: Courtesy of Roberta Baker.
