Stanford engineers have developed a new highly efficient solar cell called photon enhanced thermionic emission (PETE) that could more than double the efficiency of existing solar technology. PETE simultaneously uses both the light and heat of solar radiation to generate electricity. Unlike traditional solar panels that become less efficient as temperatures increase, PETE excels at higher temperatures. The materials needed for PETE are inexpensive and readily available, meaning the energy produced could compete with oil on cost.

1. New Type, highly efficient
Solar Cell developed
"photon enhanced thermionic emission"
Solar Energy Conversion Process Could
Double Solar Efficiency of Solar Cells _
Science Daily (Aug. 2, 2010)

2. A new process that simultaneously combines the
light and heat of solar radiation to generate
electricity could offer more than double the
efficiency of existing solar cell technology, say the
Stanford engineers who discovered it and proved
that it works.
The process, called "photon enhanced thermionic
emission," or PETE, could reduce the costs of solar
energy production enough for it to compete with oil
as an energy source.
Stanford University
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3. "This is a conceptual breakthrough, a new energy
conversion process, not just a new material," said
Nick Melosh, an assistant professor of materials
science and engg., who led the research group. "It
is actually something fundamentally different about
how you can harvest energy."
And the materials needed to build a device to
make the process work are cheap and easily
available, meaning the power that comes from it
will be affordable.
Melosh is senior author of a paper describing the
tests the researchers conducted. It was published
this week in Nature Materials.
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4. "Just demonstrating that the process worked
was a big deal,“ Melosh said. "And we
showed this physical mechanism does exist,
it works as advertised.“ SPV cells, use the
semiconducting material silicon to convert
the energy from photons of light to electricity.
But the cells use a portion of the light
spectrum, with the rest just generating heat. 4

5. At Stanford: Simultaneous use of the light and heat of the
sun to generate electricity to make solar power production
more than twice as efficient as existing methods, has been
achieved .
Unlike current PV solar panels -- which becomes less
efficient as the temperature rises -- the new process excels
at higher temperatures. Called "photon enhanced
thermionic emission," or PETE, the process promises to
surpass the efficiency of existing SPV and thermal
conversion technologies
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6. 6
Journal Reference:
1. Jared W. Schwede, Igor Bargatin,
Daniel C. Riley, Brian E. Hardin, Samuel J.
Rosenthal, Yun Sun, Felix Schmitt,
Piero Pianetta, Roger T. Howe, Zhi-Xun
Shen & Nicholas A. Melosh. Photon-
enhanced thermionic emission for
solar concentrator systems. Nature
Materials, 01 August 2010 DOI:
10.1038/nmat2814