Solid State Lighting

Michael Shur Rensselaer Polytechnic Institute ECSE, Physics and Broadband Center http://nina.ecse.rpi.edu/shur

From a Torch to Blue and White LEDs and to Solid State Lamps

Blue LED on Si, Courtesy of SET, Inc. http://nina.ecse.rpi.edu/shur/ 1 Research Areas

• Plasma wave electronics –THz resonant emission and detection • Wide band gap materials and devices – MOSHFET, UV LEDs, SAW, polarization, transport • Sensitive skin – Flexible substrates, nano gauges, electrotextiles, TFTs, OTFTs • Novel device CAD – AIM-Spice, opto/thermo/micro CAD •Lab-on-the-WEB – http://nina.ecse.rpi.edu/shur/remote • Broadband center http://nina.ecse.rpi.edu/shur • Solid state lighting http://nina.ecse.rpi.edu/shur/ 2 Talk Outline

• History of General and Electric Lighting • Advantages of Solid State Lighting • Introduction to Photometry and Colorimetry • Optimization of Solid State Lamps • Emerging applications • Vision

http://nina.ecse.rpi.edu/shur/ 3 Lighting – prerequisite of human civilization

• 500,000 years ago- first torch • 70,000 years ago – first lamp (wick) • 1,000 BC – the first candle • 1772 - gas lighting Yablochkov candle (1876) • 1784 Agrand lamp - Agrand lamp the first lamp relied on research (Lavoisier) • 1826 -Limelight - solid- state lighting device • 1876 – Yablochkov candle • 1879 – Edison bulb Limelight Edison bulb (1879) http://nina.ecse.rpi.edu/shur/ 4 History of Electric Lighting

• 1876 Pavel Yablochkov. First electric lighting device • 1879 Thomas Alva Edison. Incandescent lamp • 1897 Nernst. Filament made of cerium oxide-based solid electrolyte. • 1900 Peter Cooper Hewitt. Mercury vapor lamp. 1903. A. Just and F. Hanaman. Tungsten filament • 1904 Moor. Discharge lamps with air • 1907 H. J. Round. First LED (SiC) • 1910 P. Claude. Discharge lamps with inert gases • 1938 GE and Westinghouse Electric Corporation Fluorescent lamps.

http://nina.ecse.rpi.edu/shur/ 5 First LED (1907)

http://nina.ecse.rpi.edu/shur/ 6 Lighting in James Joyce Room Shakespeare Hotel, Bernadinu 8/8 Vilnius, Lithuania (09/05/02)

Incandescent

First LED stamp Fluorescent http://nina.ecse.rpi.edu/shur/ 7 Benefits of LED Lighting An improvement of luminous efficiency by 1% saves 2 billions dollars per year. 120

)

y 10 100 / “High

(

S n Investment Model”

U i 8

t 80 $

e 6

i n 60

o L 2

20 C 0 2000 2010 2020 2030 Year “Low Investment Model” Data from R. Haitz, F. Kish, J. Tsao, and J. Nelson Innovation in Semiconductor Illumination: Opportunities for National Impact (2000) http://nina.ecse.rpi.edu/shur/ 8 Solid State Lighting

100

80 Efficiency (lm/W) 60

40 20

0 Incandescent Halogen Fluorescent White LED White LED (2000) (2010) 120 100 Lifetime (1000 h) 80 2002 60 40 20 0 Incandescent Halogen Fluorescent White LED White LED (2000) (2010) http://nina.ecse.rpi.edu/shur/ 9 Challenges of Solid State Lighting

• Reduce cost

• Improve efficiency of light generation

• Improve efficiency of light extraction

• Improve quality of light http://nina.ecse.rpi.edu/shur/ 10 Cost of Light

Fluorescent tubes: •Incandescent bulbs: dollar per lumen 0.01 Dollar per lumen 1/1100 White LED: dollar per lumen Re LED: 0.25 (Lumileds) dollar per lumen0.1 0.66 (Nichia)

http://nina.ecse.rpi.edu/shur/ 11 Evolution of lm/package and cost/lm for red LEDs

After Roland Haitz Agilent Technologies http://nina.ecse.rpi.edu/shur/ 12

Challenges in epoxy ne light extraction θc ns

Conventional LED chip grown active layer on an absorbing substrate. absorbing substrate

High-brightness LED chip design (b) with thick transparent window layers Light escapes through 6 cones

From A. Žukauskas, M. S. Shur, R. Gaska, MRS Bull. 26, 764, 2001. http://nina.ecse.rpi.edu/shur/ 13 Progress in AlInGaP LEDs

After http://www.lumileds.com/technology/tutorial/slide2.htm http://nina.ecse.rpi.edu/shur/ 14 Light Extraction : TIP-LEDs from LumiLeDs

1000 high pressure sodium 1 kW TIP-LED

t t 100 fluorescent 1 W

w mercury vapor 1 kW

n halogen 30 W

m Standard tungsten 60 W

u 10

L AlGaInP/GaP red filtered tungsten 60 W

Top contact 1 550 600 650 700 750

Peak wavelength (nm) After M.O. HOLCOMB et al. (2001), Compound Semiconductor 7, 59, 2001). http://nina.ecse.rpi.edu/shur/ 15 Photometry: Eye sensitivity

0 10 Photopic vision (cones) V'(λ) V(λ) @ High Illumination 10-1

10-2 Scotopic vision (rods)

@ Low illumination

10-3 Relative Sensitivity

10-4

10-5 400 500 600 700 800 Wavelength (nm) Cones are red, green, and blue http://nina.ecse.rpi.edu/shur/ 16 Radiometry and Photometry

Photopic vision eye sensitivity Watt λ Φ = 683 lm W × Φ V ( )dλ υ ∫ e W/nm ω W/nm Luminous flux Wavelength (nm) υ λ I = dΦ d = 683 lm W × I V ( )dλ υ ∫ e Luminous intensity

1/60 of the luminous intensity per square centimeter of a (Candela = lm/sr – SI unit) blackbody radiating at the temperature of 2,046 Luminous efficiency: power into degrees Kelvin actuation of vision (lm/W) http://nina.ecse.rpi.edu/shur/ 17 How much light do you need?

Type of Activity Illuminance (lx =lm/m2) Orientation and simple visual 30-100 tasks (public spaces) Common visual tasks (commercial, 300-1000 industrial and residential applications) Special visual tasks, including 3,000-10,000 those with very small or very low contrast critical elements

http://nina.ecse.rpi.edu/shur/ 18 Colorimetry: Chromaticity Coordinates

1931 CIE color matching functions: purple, green, and blue λ λ 2.0 X = x( )S( )dλ _ ∫ λ z blue λ green Y = ∫ y(λ )S( )dλ 1.5 _ λ _ y Z = z( )S( )dλ x purple ∫ 1.0 X x = X + Y + Z 0.5 Y y = 0.0 X + Y + Z 350 400 450 500 550 600 650 700 750 Wavelength (nm) x+y+z = 1 http://nina.ecse.rpi.edu/shur/ 19 Color Coordinates

[Y] 1.0

520 [G] Green 530 Planckian locus 0.8 540 510 (black body radiation)

560 0.6 500 580

A 2 3

0.4 E , 600

D , 0

65 B 0 0 4 0

0 Red , 0 0 620 6,00 0 490 C 0 [R] 0 10 640 ,0 00 700 Is it really that bad? 0.2 y Chromaticity Coordinate 480 Blue Just remember: [B] [Z] 460 0.0 400 [X] White is Black! 0.0 0.2 0.4 0.6 0.8 1.0 x Chromaticity Coordinate http://nina.ecse.rpi.edu/shur/ 20 Color Mixing

•Red, green, blue appear as white

•Red and blue appear as magenta

•Green and blue give cyan 520 0.8 530 •Red and green give yellow 540 510 YG G 560 0.6

500 Y 580

0.4 600 C(W) O 620 490 640

700 0.2

y Chromaticity Coordinate Chromaticity y B 480 P 460 400 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 x Chromaticity Coordinate http://nina.ecse.rpi.edu/shur/ 21 Color Rendering

1.0

0.8 Light grayish red Light bluish green

0.6

0.4 General Color Rendering

0.2

0.0 Index 1.0 (CRI) 0.8 Dark grayish yellow Light blue aR 0.6 integrates the reflectivity

0.4

t i 0.2 data for 8

i t 0.0

e 1.0 specified samples

f e 0.8 Strong yellow green Light violet

R Special color rendering 0.6

0.4 indices, 0.2

0.0 refer to six additional test 1.0

0.8 Moderate yellowish green Light reddish purple samples

0.6

R varies up to 100 0.4 a 0.2 100 is the best. 0.0 400 500 600 700 400 500 600 700 R might be negative Wavelength (nm) a http://nina.ecse.rpi.edu/shur/ 22 Generating White Light

Phosphor-conversion Multichip white white LED LED

Phosphor layer

InGaN chip

http://nina.ecse.rpi.edu/shur/ 23 λ λ How to Optimize Solid State lamp: maximize the objective function σ (K ) Fσ ()1, …, n , I1, …, I n = K + (1−σ )Ra where σ is the weight that controls the trade-off between the efficacy, K, and color rendering index, Ra

λ1, λ2, λ3,… and I1, I2, I3 are the peak wavelengths and relative powers of the primary LEDs, respectively

For a dichromatic lamp (two primary LEDs), the optimal solutions can be obtained by simple searching within the wavelength space involving complementary pairs of blue and yellow-green LEDs. . http://nina.ecse.rpi.edu/shur/ 24 Optimization of Polychromatic Solid-State White Lamps

100 481/580 nm 464/543/613 nm 456/537/601 nm 20 80 489/591 nm 454/543/597 nm 0 60 380/569 nm -20 450/571 nm 40 3 Primary LEDs -40 2 primary LEDs 20 496/635 nm -60 0

General Color Rendering Color General Index 0 100 200 300 400 General Color Rendering Index 300 350 400 Luminous Efficacy (lm/W) Luminous Efficacy (lm/W)

http://nina.ecse.rpi.edu/shur/ 25 General CRI, Luminous Efficacy, and LED Wavelengths of Optimized Polychromatic Lamps

99.5 660 2 LEDs 99 5 640 3 LEDs 98 4 4 LEDs 2 LEDs 620 95 3 LEDs 5 LEDs 600 90 4 LEDs 3 580 80 5 LEDs 560 70 60 540 50 520 40 30 500 20 General CRI 480 10 460 5 2 440 Peak wavelength (nm)Peak wavelength 420 320 340 360 380 400 420 440 2 5 10 20 30 40 50 60 70 80 90 95 98 9999.5 Luminous Efficacy (lm/W) General CRI

The 30-nm line widths (A. Žukauskas, R. Vaicekauskas, F. Ivanauskas, R. Gaska and M. S. Shur, Optimization of White Polychromatic Semiconductor Lamps, Appl. Phys. Lett. 80, 234 (2002)). Crosses mark points that are suggested for highest reasonable CRI for each number of primary sources. http://nina.ecse.rpi.edu/shur/ 26 General color rendering index and efficacy for optimized polychromatic solid-state

lamps (color temperature TS = 4870 K)

Type of lamp Ra Efficacy (lm/W)

Dichromatic 3 430 Trichromatic 85 366 Quadrichromatic 98 332 Quintichromatic 99 324

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A. Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 27 Peak wavelengths of primary LEDs (nm) for optimized polychromatic solid-state

lamps (color temperature TS = 4870 K)

blue cyan green yellow-green amber to red

452 - - 571 -2 453 - 537 - 604 3 454 509 561 619 4 448 493 531 572 623 5

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A.Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 28 Model spectra of white emission from quadrichromatic lamp (CT = 4870 K) for different points on optimal boundary of the (K,Ra) phase distribution

K=332 lm/W AlGaInN AlGaInP R =98.5 a

K=351 lm/W R =95 a

K=362 lm/W R =90 a

Power (arb. units) (arb. Power

K=370 lm/W R =85 a

400 450 500 550 600 650 Wavelength (nm)

From R. Gaska, A. Žukauskas, M. S. Shur, and M. A. Khan, "Progress in III-nitride based white light sources", (Invited paper), Volume 4776, pp. 82-96 (2002) http://nina.ecse.rpi.edu/shur/ 29 Optimization depends on color temperature 99

2856 K 95

General CRI General 90 4870 K

80 320 340 360 380 400 420 Luminous Efficacy (lm/W) Optimal boundaries of the (K,Ra) phase distribution for quadrichromatic lamps at two color temperatures

80 603-520-452 603-520-472 603-502-452 60 603-502-472

40 629-520-472 629-520-452 From theory 20 645-520-452 to practice 0 629-502-472 645-520-472

General CRI (points) CRI General -20 629-502-452 645-502-472 645-502-452 -40 16 18 20 22 24 26 Efficiency (lm/W)

79 629-603-520-452

78 520

3- (p )

4 77 6 6 0 3 -452 - 52 472 - 0 76 - -520 5 3 0 60 2 603/520/452 - 4 5 2 75 19.8 20.0 20.2 20.4 20.6 20.8 21.0 Efficiency (lm/W)

603-520-452-nm trichromatic 100 645-603-520-452-nm quadrichromatic

-20

-40 General Color rendering (points) Color rendering a Light blue R 6 Light violet 7 Strong blue Strong R 12 Strong Strong green -60 R Strong yellow Strong 11 R 10 R R Light grayish red Light grayish 1 Light bluish green 5 R Light yellowish pink yellowish Light Dark grayish yellow Light reddish purple Strong yellow green yellow Strong R 2 8 3 13 Moderate olive green Moderate R R R R 14 R Moderate yellowish green yellowish Moderate Strong red Strong 4 9 R R

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A.Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 33 U of V/SET/RPI Versatile Solid State Lamp

Control unit Lighting fixture

Photodiode sensor PC USB interface ADC module Current regulators

Microcontroller LED array Power supply

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A. Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 34 High-power LED based Versatile White Multichip Lamp

http://nina.ecse.rpi.edu/shur/ 35 VSSL User Interface

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A. Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 36 Color Temperature Control in a Quadrichromatic Source of White Light

100 4.0 (a) L-type 10 1 S-type 3.5 520 nm

0.1 M-type 3.0 (arb. units) (arb. 0.01 603 nm 2856 K (b) Receptor sensitivity 2.5

2.0 4870 K (c)

1.5

5800 K (d) 1.0 645 nm

452 nm

Power per 3000 lm (W)Power 0.5 6504 K (e) 0.0 3000 4000 5000 6000

Spectral power density (arb. units) density Spectral power 400 500 600 700 Waweleng th (nm) Color temperature (K)

From A. Zukauskas, R. Vaicekauskas, G. Kurilcik, Z. Bliznikas, K. Breive, J. Krupic, A. Rupsys, A. Novickovas, P. Vitta, A. Navickas, V. Raskauskas, M. S. Shur, and R. Gaska, Quadrichromatic white solid-state lamp with digital feedback, SPIE 5187-24 http://nina.ecse.rpi.edu/shur/ 37 Applications of U of V/RPI/SET quadrichromatic Versatile Solid-State Lamp: Phototherapy of seasonal affective disorder at Psychiatric Clinic of Vilnius University

• Seasonal affective disorder (SAD) strikes some people in the northern latitudes • Bright white light is known to counteract SAD • The exact mechanism of treatment is not known

http://nina.ecse.rpi.edu/shur/ 38 Preliminary results for SAD Treatment

A pilot investigation of color temperature selection was carried out on healthy subjects. Preliminary results showed that subjects with the emotional scale exhibiting anxiety required light with a higher color temperature.

http://nina.ecse.rpi.edu/shur/ 39 SEMICONDUCTOR MATERIALS SYSTEMS FOR HIGH BRIGHTNESS LEDs

2000 800 600 500 400 300 200

AlN 1 C ZnS GaN ZnO SiC(4H) SiC(6H) ZnSe CdS AlP CdO SiC(3C) GaP

ZnTe AlAs InN CdSe AlSb CdTe GaAs InP Si GaSb Ge InAs UV InSb IR

01234567 Band Gap Energy (eV) http://nina.ecse.rpi.edu/shur/ 40 III-Nitride AlxGa1-xN UV Emitters require high Al molar fraction (X)

6.0 AlGaN heterostructures

350 )

m involve strain and polarization:

(

g ) 300

V 5.0

(

e Strain Energy Band Engineering

250

o a 4.0 •Quaternary

s i •Strain relief via superlattice buffers

Al Ga N m 0.3 0.7 200 E •MEMOCVD 3.0 0.0 0.2 0.4 0.6 0.8 1.0 •Non-polar substrates Al mole fraction •Homoepitaxy

Thermal and current management http://nina.ecse.rpi.edu/shur/ 41 Strain Energy Band Engineering

Use AlGaInN - quaternary Use strain controlling superlattices

Thickness, nm 60 3 50

)

e 2 40

(

e 1 30

f AlGaN

O 0 20 0.2 0.4 0.6 0.8 1

n -1 InGaN 10

B -2 0 0 0.2 0.4 0.6 0.8 1 Al Mole Fraction

)

A 0.1

(

Critical thickness as a function of Al mole fraction

h AlGaN 0 c in AlxGa1-xN/GaN: superlattice (solid line), t 0.2 0.4 0.6 0.8 1 a -0.1 SIS structure (dashed line).

i InGaN From A. D. Bykhovski, B. L. Gelmont, and M. S. Shur, -0.2

m J. Appl. Phys. 81 (9), 6332-6338 (1997)

e -0.3

a -0.4 L Molar Fraction of Al and In http://nina.ecse.rpi.edu/shur/ 42 AlN/AlGaN Room Temperature Photoluminescence

PL from edge @ L = 400 µm PL from edge @ L = 440 µm 5 nm Al Ga N 20 nm AlN 0.5 0.5 spontaneous PL

AlN epilayer Bulk AlN

substrate substrate

PL Intensity (arb. units) (arb. Intensity PL SiC substrate Luminescence intensity (arb. units) (arb. Luminescence intensity

240 260 280 300 320 Wavelength (nm) 240 260 280 300 Wavelength (nm) PL signal from MQWs on bulk AlN is approximately 28 times stronger compared to Stimulated emission at 258 nm. the structure grown over SiC. From R. Gaska, C. Chen, J. Yang, E. Kuokstis, A. From R. Gaska, C. Chen, J. Yang, E. Kuokstis, A. Khan, Khan, G. Tamulaitis, I. Yilmaz, M. S. Shur, G. Tamulaitis, I. Yilmaz, M. S. Shur, J. C. Rojo, L. Schowalter, . Deep-ultraviolet J. C. Rojo, L. Schowalter, . Deep-ultraviolet emission emission of AlGaN/AlN quantum wells of AlGaN/AlN quantum wells on bulk AlN, accepted at APL on bulk AlN, accepted at APL http://nina.ecse.rpi.edu/shur/ 43 Pulsed Atomic Epitaxy: A representative growth unit cell of PALE. New Development – MEMO-CVD

Time, sec.

http://nina.ecse.rpi.edu/shur/ 44 Ultimate heteroepitaxy: blue LED on Si

Courtesy of SET, Inc. http://nina.ecse.rpi.edu/shur/ 45 USC/SET UV LED for solid state lighting and

50 homeland security 278 nm 325 nm 338 nm 40 340 nm LED From: 30 325 nm LED A. Chitnis, V. Adivarahan, 9nm 8.5nm 10.2nm 20 280 nm LED J. Zhang, M. Shatalov, RT S. Wu, J. Yang, G. Simin, Current, mA 500 ns M. Asif Khan, X. Hu, 10 10 kHz Q. Fareed, R. Gaska,

Normalized intensity, a.u. intensity, Normalized and M. S. Shur, 0 Milliwatt power AlGaN 0246810 240 260 280 300 320 340 360 380 400 420 440 quantum well deep ultraviolet Voltage, V Wavelength, nm Light emitting diodes, physics status solidi (2003) To be published 20 0.6 340 nm

0.4 325 nm 10 pulse 280 nm 1 A

15 0.2 EQE, %

0.0 0 200 400 600 800 1000 1 10 Current, mA dc 100 mA

Power, mW 5 Output power, mW Output power, 0.1

0 270 280 290 300 310 320 330 340 350 0 200 400 600 800 1000 Current, mA Wavelength, nm http://nina.ecse.rpi.edu/shur/ 46 Sub-milliwatt power 285 nm Emission UV LED on Sapphire.

30 14 25 RT 12 dc 20 10 Rs~70-80 Ω W

15 µ 8

6 p+-GaN 10 Power, Power, Current, mA 4 p-AlGaN 5 2

SQW 0 0 02468 020406080100 + n -AlGaN buffer Voltage, V Current, mA

SL 0.20 LT-AlN RT 0.15 pulse Sapphire 500 ns, 0.5% 285.5 nm 0.10 200 mA pulsed pumping 500 ns, 10 kHz Intensity, a.u. Intensity, Power, mW Power, 0.05

0.00 260 280 300 320 340 360 380 400 420 0 100 200 300 400 500 Wavelength, nm Current, mA V. Adivarahan, S. Wu, A. Chitnis, R. Pachipulusu, V. Mandavilli, M. Shatalov, J. P. Zhang, M. Asif Khan, G. Tamulaitis, A Sereika, I. Yilmaz, M. S. Shur, and R. Gaska, AlGaN Single Quantum Well Light Emitting Diodes with Emission at 285 nm, Appl. Phys. Lett., Vol. 81, Issue 19, pp. 3666-3668 (2002) http://nina.ecse.rpi.edu/shur/ 47 Solid State Lighting Funding

Nothing comes from nothing (Fresco at Vilnius University)

http://nina.ecse.rpi.edu/shur/ 48 US DOE Mission Statement

Develop viable methodologies to conserve 50% of electric lighting load by the year 2010

From Status Report: San Francisco, California, June 24, 2002 Edward D. Petrow DOE’s Solid State Lighting U.S. Secretary of Energy Spencer Abraham Initiative For General Illumination told the United States Energy Photonics West Association that his department is January 24, 2001 exploring the use of solid-state lighting San Jose, CA utilizing Light Emitting Diodes (LEDs) as part of its ongoing campaign to reduce energy usage in the U.S. He displayed a Luxeon LED light source from Lumileds Lighting and called high-power LEDs "a revolutionary technological innovation that promises to change the way we light our homes and businesses." White 5 W 120 lm 5500 K color temperature Lumileds Luxeon http://nina.ecse.rpi.edu/shur/ 49 How energy saving will be achieved R&D Topic Area % of Goal New Light Sources 25% Solid State Lighting 45%

Advanced Electronics & 15% Integrated Controls

Improved Fixtures & 10% Market Penetration Human Factors 5%

From Status Report: Edward D. Petrow DOE’s Solid State Lighting Initiative For General Illumination, Photonics West January 24, 2001 San Jose, CA http://nina.ecse.rpi.edu/shur/ 50 DOE Energy Saving Projection 8 7 6 Baseline 5 Low SSL Penetration 4 High SSL Penetration 3 Initial 2 Quads, PEC Projection 1 0 2000 2004 2008 2012 2016 2020

Note: The projection assumes a constant primary energy consumption conversion ratio of 3.22 from end-use electricity to PEC. (source: BTS Core Databook, 2000)

From Status Report: Edward D. Petrow DOE’s Solid State Lighting Initiative For General Illumination, Photonics West January 24, 2001 San Jose, CA http://nina.ecse.rpi.edu/shur/ 51 LED Applications

http://nina.ecse.rpi.edu/shur/ 52 LED Applications Signals and Displays •POWER SIGNALS •Traffic Lights •Automotive Signage •Miscellaneous Signage

•DISPLAYS •Alphanumeric Displays •Full Color Video Displays

http://nina.ecse.rpi.edu/shur/ 53 LED Applications (Biomedical)

• MEDICAL APPLICATIONS – Phototherapy of Neonatal Jaundice –Photodynamic Therapy – Photopolymerization of Dental Composites – Phototherapy of Seasonal Affective Disorder

• PHOTOSYNTHESIS –Plant Growing – Photobioreactors

• OPTICAL MEASUREMENTS – Fluorescent Sensors – Time-Domain and Frequency-Domain Spectroscopy – Other Optical Applications

http://nina.ecse.rpi.edu/shur/ 54 LED-Based Fluorimetry

(a) (b) •Design versatility

LED PD C •Low-noise response LED PD EF FF •Electronic modulation L EF FF C L •Low heat production

http://nina.ecse.rpi.edu/shur/ 55 UV-LED Based Fluorimeter with Integrated Lock-in Amplifier

http://nina.ecse.rpi.edu/shur/ 56 LED Applications - Lighting

Parabolic Reflector •ILLUMINATION – Local Illumination – General Lighting Cone Reflector

J. IES Fresnel Lens

LED array LED Floodlight (after A.García-Botella et al., 29, 135, 2000) http://nina.ecse.rpi.edu/shur/ 57 General Lighting

http://nina.ecse.rpi.edu/shur/ 58 Solid State Lighting - To probe further:

Book A. Žukauskas, M. S. Shur, and R. Gaska, Introduction to Solid State Lighting, John Wiley and Sons, 2002, ISBN: 0471215740 Reviews/chapters: A. Žukauskas, R. Vaicekauskas, F. Ivanauskas, M. S. Shur and R. Gaska, Optimization of white all-semiconductor lamp for solid-state lighting applications, in in Frontiers in Electronics: Future Chips Proceedings of the 2002 Workshop on Frontiers in Electronics (Wofe-02) St. Croix, Virgin Islands, World Scientific Pub Co; (January 15, 2003),

R. Gaska, A. Žukauskas, M. S. Shur, and M. A. Khan, Progress in III-nitride based white light sources, in SPIE Proceedings, to be published (Invited paper)

A. Žukauskas, M. S. Shur, and R. Gaska, Solid State Lighting, in: Future Trends in Microelect , New York: Wiley, 2002, S. Luryi, J. M. Xu, and A. Zaslavsky, eds.

A. Žukauskas, M. S. Shur, and R. Gaska, Light-emitting diodes: progress in solid-state lighting, ronics:MRS Bulletin, The Nano pp. Millennium 764-769, October (2001)

A. Žukauskas, M. S. Shur, R. Gaska, Solid-State Lamps, McGraw Hill Technical Encyclopedia

M. Asif Khan, J. Yang, G. Simin, R. Gaska, and M. S. Shur, Strain energy band engineering approach to AlN/GaN/InN heterojunction devices, pp. 195-214, in Frontiers in Electronics: Future Chips Proceedings of the 2002 Workshop on Frontiers in Electronics (Wofe-02) St. Croix, Virgin Islands, World Scientific Pub Co; (January 15, 2003), http://nina.ecse.rpi.edu/shur/ E-mail: [email protected] 59 Conclusion “... it is vital to know that the LED is an ultimate form of lamp, in principle and in practice, and that its development indeed can and will continue until all power levels and colors are realized.” HOLONYAK, N., JR. (2000), “Is the light emitting diode (LED) an ultimate lamp?” Am. J. Phys. 68 (9), pp. 864-866.

http://nina.ecse.rpi.edu/shur/ 60 Appendix: Math of Color Rendering

Reference source

Sr ()λ → Sr (λ)ρi (λ), i =1,…,8 Test source

Sk ()λ → Sk (λ)ρi (λ), i = 1,…,8 USC chromaticity coordinates u = 4x ()− 2x +12y + 3 , v = 6y ()− 2x +12y + 3

General color rendering index (CRI) 1 8 Ra = Ri ∑ 8 i=1

http://nina.ecse.rpi.edu/shur/ 61 where Ri is

2 2 2 = 100 − 4.60 {[]Wki −Wri +13 [Wki (uki′ − ur )−Wri (uri − ur )] + 2 2 1 2 13 []Wki ()()vki′ − vr −Wri vri − vr } .

1 3 W = 25Y −17 c = ()4 − u −10v v

d = ()1.708v + 0.404 −1.481u v 10.872 + 0.404c c c − 4d d d u′ = r ki k r ki k ki 16.518 +1.481cr cki ck − dr dki dk 5.520 v′ = ki 16.518 +1.481cr cki ck − dr dki dk

http://nina.ecse.rpi.edu/shur/ 62 Primary Energy Consumption in Buildings by End Use (US, 1998)

Unallocated 2.6 Quads (7%) Lighting From Status Report: Other 6.0 Quads (17%) Edward D. Petrow 1.3 Quads (4%) DOE’s Solid State Lighting Initiative For Appliances General Illumination 5.0 Quads (14%) Photonics West January 24, 2001 San Jose, CA Refrigeration 36.3 Quads 2.4 Quads (7%) Space Heating 9.4 Quads (25%) Water Heating 4.1 Quads (11%) 1 Quad = 1015 BTU Ventilation Space Cooling 1.2 Quads (3%) (~8x 109 gallon of gas) 4.3 Quads (12%) http://nina.ecse.rpi.edu/shur/ Source: BTS Core Databook, August 2000, Table 1.1.7 and Industrial Building Estimate from Table 1.3.11 63 CL′

Cost of light

•Estimated from τ 6 CL′η 3 C1kWh the cost of the C1Mlmh ≈ 10 +10 P ′ η′ lamp and the L L L L electric power ′ cost of the bulb consumed divided CL C by the amount of 1kWh price of 1 kW·h power luminous efficiency lumens produced η′L P over the lifetime. L wattage For 1 Mlm⋅h, this τL lifetime of the lamp yields a cost

http://nina.ecse.rpi.edu/shur/ 64