PV Gap

Irene Said:

can we use quantum dots as a solar cell comercially?

We Answered:

Definitely!
Quantum dots offer the potential for an improvement in maximum
efficiency of solar cells from the present 25% to an incredible 70%.
They have the potential for doing this by taking advantage of some
of the properties that make quantum dots unique.
First, quantum dots allow us to increase the bandgap available for
absorption. Current photoelectric cells have only a certain specific
energy level at which electron conduction occurs; i.e. a specific
band gap. This limited band gap only takes advantage of a small portion of the energy
spectrum hitting the cell. Quantum dots, however, allow us to tune the
band gap by altering the size of the dots. Larger band gap allows the
capture of higher energy photons. Smaller band gap allows capture of
more lower energy photons, including those at the red end. By combining
quantum dots of various sizes on one cell gives us a cell that captures a large portion of the light hitting the cell
rather than wasting anything that is not at just the right wavelength.
Quantum dots may also be manufactured using mass production
techniques. They can be created in liquid colloidal solutions, and then
placed in molds to form large continuous sheets or even three dimensional arrays. This is much more efficient that current methods
which require the slow growth of perfect individual crystals of silicon or other semi-conductor materials.
All that remains right now are improvements in manufacturing techniques
to start taking advantage of these properties on a commercial scale. I expect you will start seeing mass produced solar cells using quantum dot
technology within just a couple of years. And they will not be limited to
the kinds of rigid, bulky arrays we are used to seeing. Rather, they will
be thin, flexible sheets that can be easily placed almost anywhere. They
will be woven into clothing, or included in the outer shell of laptop computers, or built right into the surface of shingles on your roof. The
possibilities are limitless~

Peggy Said:

what is the application of "quantum dots" on solar cell?

We Answered:

A team from Los Alamos National Laboratory found that quantum dots produce as many as three electrons from one high energy photon of sunlight. When today's photovoltaic solar cells absorb a photon of sunlight, the energy gets converted to at most one electron, and the rest is lost as heat. This could boost the efficiency from today's 20-30% to 65%. This work was reproduced one year later by an NREL team.

For detailed information on Quantum Dots, visit http://en.wikipedia.org/wiki/Quantum_dot…

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