OUTLINE OF TOPICS DAYS 1 2 Day

OUTLINE OF TOPICS (DAYS 1 & 2) Day 1 (General) • 1 A Overview • 1 B Technology Evolution Day 2 (Technical Challenges) • 2 Roadmap Overview • 2 A Substrates, Buffers and Epitaxy • 2 B Physics, Processing and Devices • 2 C Lamps, Luminaires and Systems Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Security Administration under Contract DE-AC 04 -94 AL 85000 JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

1 A Overview • History of Luminous Efficacy • The Grand Vision of SSL • U. S. SSL Roadmap JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

History of Lighting Technology 0. 25% JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Applications for Colored LEDs Red Traffic Light Rear Combination Lamp (Lumi. Leds) JY Tsao ∙ NASDAQ’s Giant Video Display in Times Square, New York (Jeff Tsao) SSL Promise & Challenges ∙ IMRE Singapore Programmable Lights on Ben Franklin Bridge, Philadelphia (Color Kinetics) ∙ Aug 2005

Lighting the Earth at Night (courtesy of NASA) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Projected Energy and Carbon Savings Adapted from M. Kendall and M. Scholand, “Energy Savings Potential of SSL in General Lighting Applications” (U. S. DOE-OBT study by Arthur D. Little, 2001), and EIA Statistics. Projected Year 2025 Savings SSL Promise & Challenges 35 ~120 Electricity generating capacity (GW) ∙ ~1, 800 70 ~250 85 ~300 % of Kyoto protocol ∙ 525 Carbon emissions (Mt. C/yr) JY Tsao World $ spent on Electricity ($B/yr) ~5 x US Electricity used (TWh/yr) ~3 x 7. 5 IMRE Singapore ∙ Aug 2005

Human Visual Experience Joseph Wright (1768) ∙ SSL Promise & Challenges ∙ "An Experiment on a Bird in the Air Pump“ JY Tsao IMRE Singapore ∙ Aug 2005

U. S. National Initiatives JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

US SSL-LED Roadmap Update 2002 Sponsors Editors Arto Nurmikko, Axel Scherer, Bob Davis, Weng Chow, Tom Kuech, Shuji Nakamura, Chips Chipalkatti, Nadarajah Narendran, Kevin Dowling, Alok Srivastava, Paul Martin Chap 0 Contributors Yoshi Ohno, Michael Scholand, Kate Bogart, Roland Haitz Chap 1 Contributors Dan Koleske, John Bumgarner, Christine Mitchell, Randy Creighton, Eric Jones, Sam Myers Chap 2 Contributors Weng Chow, Art Fischer, Mike Krames, Ed Stokes, Spilios Riyopoulos Chap 3 Contributors SSL Promise & Challenges Steve Denbaars, Bernd Keller, Mike Coltrin, Bob Davis, Tom Kuech, George Craford, Paul Martin, Jim George, Chips Chipalkatti Workshop Speakers ∙ Mar 2001 Roadmap - Eric Jones (SNL) Aug 2002 Update - Jeff Tsao (SNL) Technical Area Coordinators JY Tsao OIDA (Arpad Bergh), DOE (Jim Brodrick), NEMA (Kyle Pitsor) Dan Doxsee, Yongchoi Tian, Karel Vanheusden, Lauren Rohwer, Stan Weaver, Steve Richfield, Frank Steranka, Chuck Becker, James Gee ∙ IMRE Singapore ∙ Aug 2005

SSL-LED Roadmap Targets Capital Cost [$/(Mlm-hr)] 100. 00 SSL-LED 2002 10. 00 SSL-LED 2007 Incandescent 1. 00 SSL-LED 2012 0. 10 Fluorescent SSL-LED 2020 • Targets based on raw economic performance (not human factors) – Incandescence in 5 years – Fluorescence in 10 years • Ownership Cost = Operating Cost + Capital Cost 0. 01 JY Tsao 0. 10 1. 00 100 Operating Cost [$/(Mlm-hr)] ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

SSL Science and Technology Taxonomy 0 General 1 Substrates, Buffers and Epitaxy 1. 1 Substrates 1. 2 Buffers 1. 3 Epitaxy Tools 1. 4 Epitaxy Processes 2 Physics, Processing and Devices 2. 1 Semiconductor Physics 2. 2 Device Processing 2. 3 LEDs and Integrated LEDs 2. 4 Directional Emitters 3 Lamps, Luminaires and Systems 3. 1 Phosphors and Encapsulants 3. 2 Lamps and Electronics 3. 3 Luminaires 3. 4 Lighting Systems JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Sandia’s SSL Website Semiconductor light emitting devices, once limited to a narrow range of colors, now span nearly the entire visible spectrum. Someday, they may be bright, efficient and inexpensive enough to replace vacuum tubes for white lighting. Energy consumption and environmental pollution would be reduced, and the quality of the human visual experience would be enhanced, dramatically. Yet, enormous challenges lie ahead. This web-site aims to provide a comprehensive portal to the emerging knowledge that will enable the promise of solid-state lighting. JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore http: //lighting. sandia. gov/ ∙ Aug 2005

1 B Technology Evolution • Traditional vs SSL Technologies • Evolution of SSL Technology • Evolution of SSL Markets JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Traditional Lighting Color Rendering Index (CRI) Standard Incandescent Linear Fluorescent Metal Halide & High-Pressure Sodium Ownership Cost ($/Mlmh) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Solid-State Lighting Color Rendering Index (CRI) Phosphor Down. Conversion RYGB White RG Phosphors Blue LED Color Mixing RYGB White Mixing Optics RYGB LEDs Ownership Cost ($/Mlmh) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

SSL Evolution Ownership (40 x) lm/W (9 x) $/W (4. 5 x) Color Rendering Index (CRI) Costs: Ownership = Operating + Capital Electricity Power Delivery Cost Luminous Efficacy Lifetime Ownership Cost ($/Mlmh) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Impact on Industry Revenue SSL Evolution (Draft Projections) Impact on Energy Consumption Technology Diffusion (Market Penetration) Technology Evolution JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Semiconductor Industry and SSL (Draft Data) Silicon 2004 ~US$218 B Projected SSL 2015 ~US$50 B Compound Semiconductors 2004 ~US$7. 3 B High-Speed Electronics Telecom Lasers/Receivers CD Lasers DVD Lasers Red LEDs High-Power Lasers Blue/Green/White LEDs HD-DVD Lasers Energy Conversion, Imaging, Sensing Ultra-High-Speed Electronics High-Power Electronics Al. N Ga. N Al. P Ga. As In. N JY Tsao ∙ SSL Promise & Challenges Al. As ∙ IMRE Singapore Al. Sb In. P Ga. Sb In. As ∙ In. Sb Aug 2005

OUTLINE OF TOPICS (DAYS 1 & 2) Day 1 (General) • 1 A Overview • 1 B Technology Evolution Day 2 (Technical Challenges) • 2 Roadmap Subtargets/Decisions • 2 A Substrates, Buffers and Epitaxy • 2 B Physics, Processing and Devices • 2 C Lamps, Luminaires and Systems Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Security Administration under Contract DE-AC 04 -94 AL 85000 JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

2 Roadmap Overview Technology Building Block 0 Introduction to SSL 1 Substrates, Buffers and Epitaxy 1. 1 Substrates 1. 2 Buffers 1. 3 Epitaxy Tools 1. 4 Epitaxy Processes 2 Physics, Processing and Devices 2. 1 Semiconductor Physics 2. 2 Device Processing 2. 3 LEDs and Integrated LEDs 2. 4 Directional Emitters 3 Lamps, Luminaires and Systems 3. 1 Phosphors and Encapsulants 3. 2 Lamps and Electronics 3. 3 Luminaires 3. 4 Lighting Systems Totals JY Tsao Targets Subtargets Decisions Challenges 7 11 SSL Promise & Challenges 14 3 3 4 4 13 3 4 11 3 3 3 2 2 1 7 ∙ 3 2 11 ∙ IMRE Singapore 8 38 ∙ Aug 2005

Roadmap Subtargets JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Roadmap Decisions 0 General – Will the SSL-LED chip “engine” be driven at low input power densities with low cost/cm 2 and Toper, or will it be driven at high input power densities at high cost/cm 2 and Toper? – Will SSL-LED white light production be through a wavelength conversion, color mixing, or a hybrid approach? – How many colors (and in what wavelength ranges) will best balance three constraints of pure white, high color rendering and high luminous efficacy? 1 Substrates, Buffers and Epitaxy – Which semiconductor materials family will form the basis for the SSL-LED chip “engine” -Al. Ga. In. N only, or a combination of Al. Ga. In. P and Al. Ga. In. N? – *Which low-defect-density substrate or substrate+buffer combination will form the basis for epitaxial Al. Ga. In. N devices: Native Ga. N, Sapphire/Si. C + Buffer, or Removable Ga. N? 2 Physics, Processing and Devices – Will the SSL-LED light chip “engine” be based on spontaneous (LEDs) or stimulated (lasers) emission devices? – *Will the SSL-LED light chip “engine” be a single-function generator of monochromatic light, or will it monolithically integrate other functions, such as white-light production and programmable drive electronics? 3 Lamps, Luminaires and Systems – *Will SSL-LED white lighting compete with conventional lighting by emphasizing traditional attributes such as low cost-of-ownership, high efficiency and environmental friendliness, or will it compete by emphasizing new attributes such as programmability and improved interplay with building architectures and the human visual system? JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

2 A Substrates, Buffers, Epitaxy 3 Constraints on epitaxy tools and processes 2 Constraints on substrate quality Hydride In MO In H 2 O Out RF coils 1 Constraints on semiconductor materials H 2 O In 1800 rpm JY Tsao ∙ Exhaust SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Semiconductor Materials Constraints JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Substrate Constraints 6 To get lifetimes of 50, 000 hr: 5 If degradation rate is mediated by dark-line defects and scales as (rdisl) (jcurrent) e-d. E/k. T, and if Egawa, et al’s data (J Appl Phys 82, 5816 (1997)) is fit, then: 7 50, 000 hr lifetime is a tighter constraint: rdisl < 106 -108/cm 2 4 Near-unity radiative efficiency is only a loose constraint: rdisl < 107 -109/cm 2 1 In Ga. N, radiative e-h 3 As temperature recombination is increases, traps quenched within 160 nm? become leaky radii around dislocations JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore 2 In In. Ga. N, Eg fluctuations (50 me. V? ) trap e-h pairs away from dislocations ∙ Aug 2005

In. Ga. N Epitaxy Process Constraints JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

2 B Physics, Processing, Devices Courtesy of Arto Nurmikko (Brown U) 2 Power Delivery Cost JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore 1 Luminous Efficacy ∙ Aug 2005

Luminous Efficacy & Power Delivery Cost Ownership (40 x) lm/W (9 x) $/W (4. 5 x) Color Rendering Index (CRI) Costs: Ownership = Operating + Capital Electricity Power Delivery Cost Luminous Efficacy Lifetime Ownership Cost ($/Mlmh) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Luminous Efficacy: hinthextheye JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Lamp Cost per unit die Area ($/cm 2) Power Delivery Cost 105 2002 -2004 SSL Power White 103 Hi-Power IR Lasers Lo-Power Red LEDs 101 in : 02 $/W 20. 85 3 : n 20 /W i 0 $ 2 4 0. 10 -1 OLEDs? 10 -3 10 -1 103 105 Input Power Density (Win/cm 2) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Chip Size 5 Two extremes in thermal resistance (and operating temperature) subtargets 3 Two extremes in chip areal cost (and chip area) subtargets: Gain DT l l 1. 5 klm 7. 5 W 75¢ Chip Heat Sink 4 Heat conduction physics implies inverse relationship between thermal resistance and (chip area)1/2 JY Tsao ∙ SSL Promise & Challenges 2 $/chip target implies inverse relationship between chip area and chip areal cost ∙ IMRE Singapore ∙ 3. 75 W 1 Lamp targets (1. 5 klm/lamp, 200 lm/W, $3/lamp) imply overall chip targets (lm/chip, W into heat sink, $/chip) Aug 2005

2 C Lamps, Luminares, Systems 3 System-Level SSL Driving Forces 1 Color Rendering and Luminous Efficacy 2 Approaches to White Light JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Relative sensitivity for 3 types of cones Vertebrates Mammals Primates Color Rendering and Luminous Efficacy JY Tsao After Bruce Mac. Evoy After Zukauskas, et al Appl Phys Lett 80, 234 (2002) http: //www. handprint. com/HP/WCL/color 1. html ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Tri-color phosphor Fluorescent Lamp Spectrum Approaches to White Light Phosphor Down. Conversion RYGB White RYG Phosphors Blue LED Incandescence Sunlight Computer Monitor Color Mixing RYGB White Mixing Optics RYGB LEDs JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005

Color Rendering Index (CRI) SSL Driving Forces Ownership Cost ($/Mlmh) JY Tsao ∙ SSL Promise & Challenges ∙ IMRE Singapore ∙ Aug 2005