NREL Finds Quantum Dots Can Boost Solar Cell Efficiency

0 Comments | Renewable Energy Today, June 1, 2005

Researchers at the National Renewable Energy Laboratory (NREL) recently released a new study which finds that tiny nanocrystals, known as "quantum dots," are capable of producing as many as three electrons from one high-energy photon of sunlight, compared to current photovoltaic solar cell technology, which converts one photon of sunlight into only one electron.

"We have shown that solar cells based on quantum dots theoretically could convert more than 65 percent of the sun's energy into electricity, approximately doubling the efficiency of solar cells," said NREL researcher Arthur Nozik.

NREL said the findings confirm the work of Nozik, who in 2000 predicted that quantum dots could increase the efficiency of solar cells, through a process known as "multiple exciton generation" (MEG). Last year, researchers at Los Alamos National Laboratory demonstrated the electron multiplication phenomenon predicted by Nozik using quantum dots made from lead selenide.

In the new study, the lab said the NREL researchers, working in conjunction with theorists from the Naval Research Laboratory (NRL), demonstrated MEG in quantum dots of lead sulfide.

"The NREL/NRL work not only shows higher overall efficiency for multiple exciton generation, it also establishes that the process occurs with lower photon energies, meaning it could make use of an even greater portion of the sun's light spectrum," said the lab.

Contact: NREL, phone 303-275-4090, website http://www.nrel.gov.

(EIN STAFF: 5/23)