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Quantum Dots
00:12 - 05:31
Quantum dots are nano sized crystals. They are used in display screens because they are able to emit lights of different colors. Researchers are looking to use these dots to create a new type of solar cell.
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Video Transcript
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Energy Information Administration over 85 percent of the electricity generated in the United States
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comes from coal natural gas
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and nuclear energy
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power plants that process these energy sources
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are massive in scale
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but one of the most efficient ways to convert energy
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is through a crystal
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made on a scale so small some even 15 atoms in diameter
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it can't be seen by the naked eye
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a quantum dot
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when something is quite tiny it actually
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makes itself perfect and that's why the nanoscience is so interesting to people because
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we can make perfect things
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very easily
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Paul Oliver sato's is a pioneer of nanoscience and a professor of chemistry and Material Science
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at the University of California Berkeley
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by studying materials just nanometers or
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billionths of a meter in diameter
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his lab with funding from the National Science Foundation
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has perfected the science
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of producing
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nano-sized crystals called Quantum dots
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these Quantum dots convert energy in the form of light into nearly every color on the visible spectrum
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bigger Quantum dots emit colors with longer wavelengths like red while smaller dots emits shorter wavelengths such as the color green
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the way to make these nanoparticles
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and to control their size very very precisely at the level of distaff
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few atoms
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that's what we've developed over quite a long time in my laboratory
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when Quantum dots of different sizes are grouped together by the billions
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they produce Vivid colors
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that have changed the way we look at display screens
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the initial research funded by the NSF has found its way into many applications including a nano technology company called Nano sis
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which produces 25 tons of quantum dot materials every year
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enough
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for approximately six million 60-inch TVs
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what we have here
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is
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a
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plastic film
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that contains inside of it
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quantum dots
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very tiny
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tiny crystals made out of semiconductors
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it actually contains
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two sizes of nanoparticle
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a very small size that emits a green color
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and a slightly larger size it emits a red color of light
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the film is embedded into tablets tell
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New Visions and laptops to enhance their displays with brilliant color
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one of the things that we learn about vision
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is that we have receptors in our eyes for green red and blue colors
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and if we want to really high quality display
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we need to match
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the light emission from our display to The receptors
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in our eyes
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all of a sudden has his next challenge is using Quantum dots as a renewable energy source nanotechnology research and development is already being applied
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to energy conversion in batteries but olive Asados is looking for a new way to efficiently Harvest energy from the Sun just point four percent of the
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energy produced in the United States is solar silicon solar panels were once the hope of the future of solar energy and all of us Otto's and his
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developed a version containing Quantum dots that could be manufactured inexpensively
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around the time we made that invention
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the world of energy changed all of a sudden very dramatically
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the big manufacturers in China
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started to mass-produce Conventional solar cells
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and they made them very well
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and they made them at large scale
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and the price just dropped it just went
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like that
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members of his team at Berkeley
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we are now on a quest to develop a plastic film what they call a quantum dot luminescent concentrator
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that can be applied to a surface such as a roof to help solve the power problem
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eventually we thought of a different way to use these Quantum dots
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where
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instead of making a photovoltaic
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we actually use their luminescence
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and we make what's called a luminescent concentrator
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which is a different kind of plastic film that absorbs light and it actually directs through
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presents all the light to a tiny spot
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all of us Otto says his quantum dot luminescent concentrator could make solar cells twice as efficient because it would collect more of the energy where
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the Sun's light is most intense
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his group is currently developing a prototype
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and exciting next step for the future of renewable energy and nanoscience
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and the Ana Science is really just beginning
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we are learning
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the rules
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that govern matter on very tiny length scales
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yes and as we learn those rules
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we're also learning
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how to design materials
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in a completely different way
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materials that could Advance the way we produce solar power
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and Forge a new frontier in renewable energy
