Sunday, March 16, 2008


Rainbow Solar Cells
6 March 2008, 17:02

Categories: Quantum-Dots smt-energy-photovoltaic

It has been known that quantum dots (QDs) emit light, as shown above, and that the wavelengths of light that are emitted are tuned to the size of the QDs. Now researchers at Notre Dame University in Indiana have used quantum dots of varying size to absorb light, and have used that energy generate power. When exposed to certain wavelengths of light, the cadmium selenide (CdSe) quantum dots release free electrons into titanium dioxide nanoparticles and nanotubes, creating a current. Interestingly, QDs of different sizes react by absorbing different wavelengths of light (e.g. the smaller quantum dots absorb shorter wavelengths of the solar spectrum). Hence, an array of quantum dots of varying size will absorb a broader spectrum of light, which might lead to next-generation, high-efficiency PVs called “rainbow solar cells.”


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