1. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 1/8 (Lighting and) Solid-State Lighting: Science, Technology, Economic Perspectives Work at Sandia National Laboratories was supported by Sandia’s Solid- State-Lighting Science Energy Frontier Research Center, funded by the U.S. Department of Energy, Office of Basic Energy Sciences. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy’s National Security Administration under Contract DE-AC04-94AL85000. Earth at Night (courtesy of NASA) Jeff Tsao Physical, Chemical & Nano Sciences Center Sandia National Laboratories Acknowledgements Mike Coltrin Mary Crawford Yoshi Ohno Jerry Simmons Paul Waide Jon Wierer Night arrives between Europe and Africa; digital composite of archived images taken by several Earth- orbiting satellites and ocean-faring ships; courtesy of NASA; http://apod.nasa.gov/apod/ap030324.html

2. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 2/8 Artificial Lighting and Human Productivity CoL ($/Mlmh) ≃ CoE/η 1 10 1 10 2 10 3 10 4 10 5 CoE ($/MW e h) Luminous efficacy η (lm/W e ) 10 -2 100% Efficiency 10 -1 1 10 1 10 2 10 3 1 10 1 10 2 10 3 10 4 10 5 CN 1993 WRLD-NONGRID 1999 WRLD-GRID 2005 UK 1800 UK 1850 UK 1750 UK 1700 UK 1900 UK 1950 UK 2000 AU+NZ 2005 FSU 2000 OECD-EU 2005 JP+KR 2005 CN 2005 CN 2006 US 2001 10 1.5 10 2.8 10 4.3 Candles Gas Kerosene HID Fluorescent Incandescent SSL? 10 -5 10 -2 10 1 10 4 β·gdp/CoL [Mlmh/(per-yr)] per capita consumption of light φ [Mlmh/(per-yr)] 10 4 10 1 10 -2 10 -5 CN 1993 WRLD-UNDEV 1999 WRLD-DEV 2005 UK 1800 UK 1850 UK 1750 UK 1700 UK 1900 UK 1950 UK 2000 AU+NZ 2005 FSU 2000 OECD-EU 2005 JP+KR 2005 CN 2005 CN 2006 US 2001 10 5.4 Tsao and Waide, “The World’s Appetite for Light: Empirical Data and Trends Spanning Three Centuries and Six Continents,” to be submitted to LEUKOS 0.0072 $/(per-yr) $/Mlmh EfficiencyConsumption 0.72% = US$440B / US$60T 6.5% = 1 TW c / 16 TW c Tsao and Waide, “The World’s Appetite for Light: Empirical Data and Trends Spanning Three Centuries and Six Continents,” to be submitted to LEUKOS

3. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 3/8 Color Rendering Index (R a ) 400 500 600 700 Wavelength (nm) 800 400 0 Human Eye Response (lm/W) 80 70 60 0 0 0.4 0.8 Color Rendering Index (R a ) Relative Reflectances Munsell Samples 1-8 Luminous Efficacy (lm/W) 300 350 400 450 8 1 7 2 6 3 5 4 7 8 CRI 85 400 lm/W 459 nm 535 nm 614 nm 573 nm J.M. Phillips, et al, “Challenges to Ultra-Efficient SSL”, Laser & Photonics Reviews (2007). Calculations based on white LED simulator 5-3 (Y. Ohno, NIST). 1.0 0.5 Relative Power 0.18 0.24 0.37 0.23 All linewidths 1-nm FWHM 100 nm 200 nm Characteristics of “100%-Efficient” Lighting 90 80 70 60 90 CCT = 3,800K R 9 = R a /4

4. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 4/8 Efficiencies of Actual Lighting Technologies 3.5%-Efficient Incandescent CCT 3,000K 14 lm/W 21%-Efficient Fluorescent CCT 3,500K 85 lm/W Courtesy of Lauren Rohwer 14%-Efficient 58 lm/W SSL Commercial Late-2009 Warm-White CCT 3,100K Driven at 0.7A 100%-Efficient SSL CCT 3,800K 400 lm/W All spectra normalized to 1W wallplug power 0 200 400 600 Human eye response (lm/W) Human eye response (photopic)

5. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 5/8 Anatomy of State-of-Art Commercial SSL Phosphor/Package54% Internal quantum effic90% Stokes deficit76% Scattering/absorption80% Spectral78% Blue LED33% Joule85% IQE at low power70% Droop at high power70% Light extraction80% http://bobbymercerbooks.com 1 mm 0.7A Thin-Film Flip Chip (TFFC) schematic courtesy of Jon Wierer ε = 14% η = 58 lm/W CRI = 85 CCT = 3,100K

6. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 6/8 Technology Grand Challenges for Luminous Efficacy Courtesy of M. Krames, Philips-Lumileds 1W LEDs 350 mA Fill in the red-yellow- green gap Eliminate blue LED droop Narrow-linewidth shallow-red color conversion Rate constants for 510nm LED, after UT Schwarz, “Emission of biased green quantum wells in time and wavelength domain,” SPIE Proc 7216, 7216U-1 (2009). 0.1 1.0 10 100 1,000 10,000 J (A/cm 2 ) 0.1 0 ε IQE 0.2 0.3 k (ns -1 ) 0.01 0.001 0.1 1 Schockley-Read-Hall Auger- like Spontaneous Emission Shockley-Read-Hall Spontaneous Emission Auger-like Target: 200 A/cm 2 1 23 Wavelength (nm) Luminous Efficacy (lm/W) Spectral power distribution (W/nm) 614 Human eye response State-of-art LED 456 614 456535573

7. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 7/8 0.01 0.1 1 10 100 CoL ope = CoE/η ($/Mlmh) CoL cap = $ Win /[η∙τ] ($/Mlmh) 100 10 1 0.1 0.01 Incandescent Fluorescent 2005.8 2007.2 2008.5 1:6 Ratio Phosphors↑ B LED↑ RGB Perfect 2004.8 0.35A 0.7A 1.5A HID 2009.7 What about Cost of Light? 2000 2005 2010 2015 2020 Year CoL = CoL cap + CoL ope ($/Mlmh) 100 10 1 0.1 Incandescent Fluorescent “Perfect” SSL 2008.3 2011.8 SSL 2011.8 HID Adapted from JY Tsao, ME Coltrin, MH Crawford, JA Simmons, “SSL: An Integrated Human Factors, Technology and Economic Perspective,” Proc IEEE (to be published). CoL cap is already ~CoL ope /6, so η is the key 2012 may be the beginning of “the transition” Adapted from Navigant, “U.S. Lighting Market Characterization,” U.S. DOE (2002); and from JY Tsao, ME Coltrin, MH Crawford, JA Simmons, “SSL: An Integrated Human Factors, Technology and Economic Perspective,” Proc IEEE (to be published).

8. JY Tsao ∙ SAND2010-1090C ∙ Photonics West 2010 Jan 26 ∙ 8/8 Earth at Night (courtesy of NASA)