Imagine
if the next coat of paint you put on the outside of your home generates
electricity from light—electricity that can be used to power the
appliances and equipment on the inside.
A
team of researchers at the University of Notre Dame has made a major
advance toward this vision by creating an inexpensive “solar paint” that
uses semiconducting nanoparticles to produce energy.
“We
want to do something transformative, to move beyond current
silicon-based solar technology,” says Prashant Kamat, John A. Zahm
Professor of Science in Chemistry and Biochemistry and an investigator
in Notre Dame’s Center for Nano Science and Technology (NDnano), who
leads the research.
“By
incorporating power-producing nanoparticles, called quantum dots, into a
spreadable compound, we’ve made a one-coat solar paint that can be
applied to any conductive surface without special equipment.”
The
team’s search for the new material, described in the journal ACS Nano,
centered on nano-sized particles of titanium dioxide, which were coated
with either cadmium sulfide or cadmium selenide. The particles were then
suspended in a water-alcohol mixture to create a paste.
When the paste was brushed onto a transparent conducting material and exposed to light, it created electricity.
“The
best light-to-energy conversion efficiency we’ve reached so far is 1%,
which is well behind the usual 10 to 15% efficiency of commercial
silicon solar cells,” explains Kamat.
“But
this paint can be made cheaply and in large quantities. If we can
improve the efficiency somewhat, we may be able to make a real
difference in meeting energy needs in the future.”
“That’s why we’ve christened the new paint, Sun-Believable,” he adds.
Kamat
and his team also plan to study ways to improve the stability of the
new material. This research was funded by the Department of Energy’s
Office of Basic Energy Sciences.
