Using Nanotechnology For Novel Energy Applications

Using Nanotechnologyfor Novel Energy ApplicationsAlexandra BoltassevaAssistant ProfessorBirck Nanotechnology CenterPurdue University

What is Nanotechnology?Nanotechnology: Technology at the nanometer length scaleNanometer: 10-9 or 0.000000001 meterImage: “Scitable” by Nature Education

http://www.howstuffworks.com/nanotechnology.htm Unprecedentedmultidisciplinaryconvergence ofscientists dedicated tothe study of a world sosmall, we can't see it. Nanotechnology is sonew, no one is reallysure whatwill come of it

The Beginning The idea of nanotechnology began withfamous physicist Richard Feynman"I would like to describe a field, in whichlittle has been done, but in which anenormous amount can be done inprinciple What I want to talk about is the problemof manipulating and controlling things ona small scale "

The Beginning 1959, APS meeting, Caltech"There's Plenty of Room at the Bottom""The principles of physics, as far as I can see, do notspeak against the possibility of maneuvering things atomby atom."Feynman proposed using a series of robot arms constructever-smaller robot arms, until the arms get so small thatthey are able to manipulate individual atoms.

The Beginning ’’Amusing,entertaining,informativeand a classicin the history anotechnology.html

What is so Special aboutNanotechnology?Nanotechnology can: Make things smaller – allowing us to make extremelysmall devices (such as implantable devices). Alsoallows to fit more technologies onto a chip Enable Revolutionary Technologies that have nomacro-scale equivalents. Physics behaves verydifferently at the nano-scale, and we can utilize thesenew physical properties to develop technologies andproducts that would be impossible withoutnanotechnology.

How can you studyNanotechnology? These devices are much smaller than we can see with our eyes, oreven under a regular microscope.We need special tools to create or even “see” nano structuresThese tools must be kept in special labs that isolate the devices from: Vibrations – even small movements can make it impossible tosee or create the structures Dirt and dust – just one piece of hair is about 10,000 times largerthan the nanostructures, and can completely destroy the device’soperability Humidity, and temperature changes also have a large impact onthe nanostructures’ physical properties and affects the materials’performanceThis is why we built the building you are in right now!

Birck Nanotechnology Center Built in 2005 for 58 Million (excluding equipment) Specially designed to reduce and eliminate vibrations, dirt anddust, humidity and temperature changes Largest and cleanest university cleanroom in the United States Entire building: 187,000 sq. ft., Cleanroom: 25,000 sq. ft., andAdditional Lab Space: 22,000 sq. ft. 180 graduate students, 45 faculty, 21 clerical and technical staff

Research at the BNCNanophotonics to control and manipulate light on the nanometerlength scaleNanoelectronics to develop smaller and faster electronic devicesNanobiotechnology to study biological systems at the nanometerscaleNanomaterials to create and study new materials at the nanometerlength scaleNanoelectromechanical systems to create and study movingsystems at the nanometer length scaleWho does research at the BNC?The Students and Professors you will meet today!

Using Nanotechnology for NovelEnergy ApplicationsNanophotonics, Nanoelectronics, Nanobiotechnology,Nanomaterials, Nanoelectromechanical systemsEach of these topics are showing great promise for the future ofenergy collection, generation, storage, and efficiencyToday, we will discuss:1. Thermoelectrics: Scott Finefrock & Sumeet Kumar2. Photovoltaics: Caleb Miskin3. Nanophotonics: Paul R. WestTour of our building

Fundamental ConceptsScaling down the size of materials to the nanoscaleprovides new physical phenomena including: Electronic properties of solids (nanoelectronics)- Amount of surface area drastically affects amaterial’s electronic propertiesGrapheneImage courtesy of BBC News GCSE BitesizeJannik C. Meyer, et. al, Nature 446, 2007

Fundamental ConceptsScaling down the size of materials to the nanoscaleprovides new physical phenomena including: Optical Properties (nanophotonics)-Drastically new optical properties arise whena material is the same size or smaller than thewavelength of lightWavelength 500nm 50nm

Thermoelectrics:Power Generation, Cooling, and NanomaterialsSumeet Kumar – Purdue Mechanical EngineeringScott Finefrock – Purdue Chemical EngineeringProfessor Timothy Fisher – Purdue Mechanical Engineering

How does a thermoelectric generator work?Top side is hot, bottom side is coldElectrons carry heat so they move from hot to coldMoving electrons create usable electric power!Image taken from: Nemir D., Beck J., Rubio E. & Alvarado M, “Materials for Energy:Solid state Thermoelectric Generation”, 2010Stratified Schematic of a thermoelectric moduleImage taken from: Snyder G.J.& Toberer E.S., ”Nature Materials” 7(2008) 105-114

Thermoelectric materialsQuestion: How do I measure howgood a thermoelectric material is?Answer: ZTHigher ZT Æ Higher EfficiencyZT S2σT/kSeebeck coefficient (S) How much energy doheat-carryingelectrons have?Electrical conductivity (σ)Thermal conductivity (k) How easily doelectrons move?How easily does heatmove?

What materials have high ZT?ZnO ?Bi2Te3 ?Cu ?MaterialMaterial type S σkZT iconductor20010411CuMetal7.610740010-3Ma, N., Li, J.-F., Zhang, B. P., Lin, Y. H., Ren, L. R., & Chen, G. F. (2010). Journal of Physics and Chemistry of Solids, 71(9), 1344-1349.Allison, S. C., Smith, R. L., Howard, D. W., González, C., & Collins, S. D. (2003). Sensors and Actuators A: Physical, 104(1), 32-39.Copper. (2012, June 04). Retrieved from http://en.wikipedia.org/wiki/CopperTelluride Chemical. Triveni Interchem Private Limited. (2012, June 06). Retrieved from http://www.triveniinterchem.com/telluride.htmlZinc Oxide. (2012, June 06). Retrieved from http://en.wikipedia.org/wiki/Zinc oxideYan, X., Poudel, B., Ma, Y., Liu, W. S., Joshi, G., Wang, H., Lan, Y., et al. (2010). Nano letters, 10(9), 3373-8.

How can nanoscale materials have higher ZT?High energy electronHeat wavesLow energy electronImage taken from: Vineis, C. J., Shakouri, A., Majumdar, A., & Kanatzidis, M. G. (2010 Advanced materials, 22(36), 3970-80.

Experiments show nanoscale materials have higher ZTNanoscale sample 1Nanoscale sample 2Nanoscale sample 3Standard sampleJoshi, G., Lee, H., Lan, Y., Wang, X., Zhu, G., Wang, D., Gould, R. W., et al. (2008). Nano letters, 8(12), 4670-4.

Thermoelectric fanThermoelectric power generation based on Seebeck effectImage : Model TD-8550 Thermoelectric Converter, Pasco Scientific Co., Hayward, CA.Stanislaw Bednarek, Thermoelectric motor, AJP 63, 1051-1052 (1995).Image URL 30 02.htm

Thermoelectric coolerPeltier cooling effectImages taken from : thermoelectric-cooler-1462472.html (URL)

Waste Heat Recovery Systems40% is wastedthrough exhaust gasIllustration of the location of a thermoelectric generator in a vehicleImage taken from: Fairbanks J.W., “Vehicular Thermoelectrics: A New Green Technology”, DEER (2001), Michigan

Thermoelectric Generators in AutomobilesFord Lincoln MKTGM Chevrolet SuburbanBMW X6Image taken from: Fairbanks J.W., “Vehicular Thermoelectrics: A New Green Technology”, DEER (2001), Michigan

Photovoltaics:converting sunlight into electricityCaleb MiskinSolar Research Group6/15/12

How long have humansused solar energy

Since the beginning

7th Century BC

3rd Century BCRomans used parabolic mirrors to light torches

2nd Century BCLegend of Archimedes: “The Death Ray”

The Solar Economy

What is Photovoltaics (PV)? The direct conversion of sunlight toelectricity using semiconductors

History of Photovoltaics 1883: Charles Fritz coated Se with Au. 1954: Silicon solar cell invented at Bell Labs

Benefits of PV The ultimate renewable resource Abundant– More energy from the sun reaches the earthin an hour than humans use in an entire year! Requires less land than mining fossil fuels Clean Improved national security

How much area is needed?Prof. Nate Lewis (CalTech)

Challenges Cost: Oil and coal are still cheaper– Manufacturing and materials can be veryexpensive Storage: Need to be able to store theenergy for use during the night and oncloudy days Toxic waste– Many cells contain toxic chemicals– Need for robust recycling programs

Purdue takes on the challenge Thin-film solar cells from nanocrystal inksusing earth-abundant materials– Lower material costs– Possibility for inexpensive printable solar cells– Flexible for use everywhere

A Novel Material Copper Zinc TinSulfide/Selenide(CZTSSe)– Cu2ZnSnSySe1-y All materials are relativelycheap, abundant, and lesstoxic than current PV cells Efficiency as high as 10%and improving quickly

NanocrystalsynthesisFilm coatingFinished Device2.5 cmCZTSInk FormulationFurther Processing

Solar cells inactionVolunteer?

Controlling Refractive Indexfor Improving PhotovoltaicLight CollectionProfessor Alexandra BoltassevaPaul R. West06/15/2012

Find the Path of Shortest TimeALandB

Find the Path of Shortest TimeA?Have to travela much furtherdistanceLandWater?Have to swimlong distancethrough thewaterB

Characteristics of Light Light travels at the ultimate speed limit of the universe300,000,000 m/s or 671,000,000 mph through space Light travels more slowly in any other material (glass,water, etc.) The amount that light is slowed in these materials iscalled the material’s “refractive index” Example: Glass has a refractive index of 1.5. 1.5 or 200,000,000 m/s Because light will always take the path of least time, itwill always bend inward into these materials

Refractive Index Demon 1.00n 1.30Water

Gradient Refractive Index Demon 1.00n 1.30n 1.40n 1.50“Slower Materials”(Higher Refractive Index)

Gradient Refractive Index Demo“Slower Materials”(Higher Refractive Index)Gradient Index Materialhttp://www.youtube.com/watch?v A7xKDxM LEk

Metamaterials Using Nanotechnology, we are able to creatematerials of almost any refractive index (includingnegative index!) We can also create materials with opticalproperties that are beyond anything that can befound in nature The greek word for “beyond” is “meta”, thereforewe call these materials “metamaterials” Using metamaterials, we can create devicesincluding invisibility cloaks and optical black holes

Optical Black HolesIncoming Light

Optical Black HolesIncoming LightPVCell

Thank You!Questions?

the nanostructures’ physical properties and affects the materials’ . Using Nanotechnology, we are able to create materials of almost any refractive index (including negative index!) We can also create materials with optical properties that are beyond anything that can be