Outline Motivation: the Global Energy Crisis Review current PV technology Inorganic Nanocrystal solar cell Benefits Research results Future potential NanoPaint™ for charging electric vehicles
Global Energy Issues Limited supply of fossil fuels Energy security Political instability Economics Environmental: CO 2, global warming, pollution …. all this combined with an increasing population!
Solar energy that strikes the earth’s surface per hour: 4.3 x J World energy consumption in one year: 4.1 x J
Solar Cell Operation
Figures of Merit Open circuit voltage, V OC Short circuit current, I SC Energy conversion efficiency, η Thermodynamic efficiency limit Quantum efficiency, EQE and IQE Maximum power point, P MAX Fill Factor, FF
Courtesy of L.L. Kazmerski, NREL PV Progress in Research
Nanocrystal Solar Cell
What are nanocrystals ? 2 ~ 10 nm 10 ~ 50 atoms EgEg 1S(e) 1P(e)
Why Nanocrystals Solar Cell? Low-Cost Large area Flexible substrate Solution process Printing
Assumption in Shockley-Queisser Approach which circumvents assumption ExamplesTheoretical efficiency One photon = one electron-hole pair Multiple absorption path solar cells Impact ionization 42% One quasi-Fermi level separation Multiple energy level solar cells Intermediate band Quantum well solar cells 87% Constant temperature = cell temperature = carrier temperature Multiple temperature solar cells. Hot carrier solar cells 66% Why Nanocrystals Solar Cell ? 30%
P3HT/CdSe nanorods Hybrid Wendy U. Huynh, Janke J. Dittmer, A. Paul Alivisatos. Science 295, 2425 (2002) poly-3(hexylthiophene)
CdTe/CdSe nanorods Gur I, Fromer N. A, Geier M. L, Alivisatos A. P. Science 2005; 310:
CIGS Nanoparticle Precursor Inkjet printable Roll-to-Roll
CIGS Nanoparticle Precursor Vijay K. Kapur*, Ashish Bansal, Phucan Le, Omar I. Asensio. Thin Solid Films 431 –432 (2003) 53–57
CIGS Nanoparticle Precursor
Comparison P3HT/CdSe NRCdTe/CdSe NRCIGS NP Isc (mA/cm 2 ) Voc (V) Fill Factor Efficiency (%) SubstrateITO/Glass GlassMo foil PrintabilityPoor Good (inkjet/screen printing) Temperature LowMedium ReliabilityNon-stableAir stableAir Stable EnvironmentalUnfriendly Friendly
NanoPaint™ for Solar Car
Solar Car North American Solar Challenge Cars drive at speed limit: 65 mph Winning time: 51 hours, 41 minutes, and 53 seconds University of Michigan Solar car University of California Berkeley Solar Car
Solar Electric Vehicles Astrolab solar concept car from Venturi Electric Solar cells: 21% efficient 1 Day of sun=11 miles
Solar Electric Vehicles 1992 Mazada 929 Luxury Sedan Solar cells run fan to cool car and can recharge the car’s battery
Solar Electric Vehicles 2010 Prius Solar roof package: $3,600 Powers fan to cool the interior by 20 degrees Only available for certain models
Solar Electric Vehicles Solar Electric Vehicle photovoltaic module 16% efficient, 215 Watts 1 Day of sun =range of 5 to 8 miles $4,000
Solar Electric Vehicles Disadvantages of models Cost: single crystalline Weight Structure Solution: Solar Cells based on CIGS nanoparticles “Solar Cell NanoPaint™” Source:
Solar Cell NanoPaint™ Our painting process of the CIGS nanoparticle on the solar car was covered by National Geographic Channel
Solar Cell NanoPaint™ Market Comparison Solar Electric Vehicles Solar Cell NanoPaint™ Optimized Solar Cell NanoPaint™ MaterialSingle CrystallineCIGS Nanoparticle Efficiency16%10%19% WeightModeratelowLow Area1.507 m m 2 LifetimeLong-20 yearslong-20 yearsLong-20 years Power Output215 Watts767 Watts1457 Watts Driving range5-8 Miles18-28 Miles34-51 Miles Environmental Hazard moderateLow Cost$4,000low-$2000Lower-$1500
Solar Cell NanoPaint™ Market Analysis Increasing hybrid electric vehicle sales will drive demand for Solar Cell NanoPaint™ Market Analysis MarketHybrid Electric vehicles Total number of Vehicles in the US247 Million Number of Hybrid Vehicles currently available in US 1-2 Million Revenue Assuming 1% Conversion of Available Hybrids 40 Million Dollars
Hybrid Sales In the US Source:
Conclusion Photovoltaics Nanoparticle Systems P3HT/CdSe CdTe/CdSe CIGS nanoparticle CIGS NanoPaint™ Solar Cell Solar hybrid electric vehicle