Quantum Leaps in Quantum Dot Research

Solar cells in the future may be more efficient, thanks to scientists at the Colorado School of Mines.

Physicist Mark Lusk and his colleagues used high-performance computers to show that tiny light-absorbing particles, called quantum dots, can use the sun’s energy to generate more electricity in solar cells and produce less unnecessary heat. 

The work supports a controversial idea called multiple exciton generation.  In solar cells, electrons obtain energy by absorbing a solar photon.  The multiple exciton theory hypothesizes that a single energized electron could then transfer its energy to two or more electrons. 

If the theory proves true we’ll be able to get more electricity out of the solar cell.

Lusk and his colleagues determined that quantum dots make this multiple exciton process more effective.   They found that the quantum dots could be tuned to the wavelength – or color – of the incoming solar radiation.   So a solar cell could be made of a collection of different sizes of quantum dots to harvest the rainbow of colors in the sun.

Experimentalists are now working to validate these computer simulations in the laboratory so they may be applied to solar cells.  The results of the School of Mines study were published in the April issue of ACS Nano.