sun development 2012rdworkshop

7/28/2019 Sun Development 2012rdworkshop

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Decai Sun, Ph. D

DOE SSL R&D Workshop, Atlanta

February 1, 2012

Challenges and Opportunities for HighPower White LED Development

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DOE SSL R&D Workshop, Atlanta, Decai Sun, February 1, 2012 2

Outline

Opportunities for Cost Reduction of High Power White LED Packages

Solutions to Raise Performance of High Power Warm White LEDs


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DOE SSL R&D Workshop, Atlanta, Decai Sun, February 1, 2012

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LED Package Evolution in Philips Lumileds

Lead frame based HP LED packages

Custom designed for non-general lighting applications

Portable, automotive, traffic signal and emergency vehicle lighting, etc

Lagging behind ceramic based HP LED packages in cost

Powerhandlin

gperLED(W)


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Low and Mid-Power LED Packages and COB

Low and mid-power LEDs are leading in therace of lm/$ approaching 400 lm/$

Standardized package design

Lower package and die cost

Improvement in efficacy

High volume from BLU

COB package development Scalable in size and light output

Easy to manufacture and copy

Simplify optical design and LED engine assembly

5630 SMD, 0.5 W
http://www.google.com/url?q=http://bridgelux.com/media-center/press-releases/bridgelux-goinggreen-silicon-valley-100-winner/&sa=U&ei=_TkHT-q_FoXjiALxluWWCQ&ved=0CCcQtwIwCQ&usg=AFQjCNElkJbHZ2JR5uI5ZQKOV_GUpQD_Ww


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Future Cost Reduction of High Power LEDs

Do we need to look beyond die on ceramic

package for cost reduction?

What is the requirement or constraint?

Thermal handling capability

Light extraction/package efficiency

Reliability and long life

Lens-free LED package is preferred in

certain applications

Package innovation & standardization will

help to drive down cost
http://www.google.com/imgres?imgurl=http://www.letsgodigital.org/images/artikelen/30/luxeon-k2-with-tffc.jpg&imgrefurl=http://www.letsgodigital.org/en/17475/luxeon-k2/&h=428&w=530&sz=81&tbnid=v9onp1aZ_5QwcM:&tbnh=107&tbnw=132&prev=/search?q=luxeon+k2+photo&tbm=isch&tbo=u&zoom=1&q=luxeon+k2+photo&hl=en&usg=__4pJPNIJoO1e7J8sJE75I3cvRYkM=&sa=X&ei=7EynTtHNDIqqiAKA4andDQ&ved=0CBIQ9QEwAA


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How to Close the lm/W Gap between WW and CW LEDs

The lm/W gap between WW LEDs

and CW LEDs is up to 30% or more

How to close the efficacy gap? Development of narrow red

phosphors and QD materials

Hybrid WW consisting of overly-

converted CW (OW) plus AlInGaP red

LED

DOE SSL MYPP 2011

350 450 550 650 750

SpectralPowerDistribution

(noramalized)

Wavelength (nm)

CCT ~2700KPhotopic Response

30nm FWHM red, 90 Ra,LE ~370 lm/Wopt

today ~80 Ra, LE ~315lm/Wopt


7/13DOE SSL R&D Workshop, Atlanta, Decai Sun, February 1, 2012 7

Hybrid Warm White LEDs

Approach InGaN OW LEDs plus AlInGaP direct red LEDs

Advantages

High efficacy High CRI

High R9

CCT tuning



Record Demonstration of WW LED by Epistar

216 lm/W at 2700K and CRI of 87 using OW plus HV red Chip size, operation temperature and color coordinates unknown

(Source: Epistar website 12/2011)

(Photo from 12/2010Epistar report of 170lm/W 2700K record)



Opportunities for Hybrid WW LEDs

General:

High efficacy

High CRI warm white

Retail:

Tunable white for scene setting

Food spectrum

Hospitality: 2200 K warm white

Warm dimming



LED Engines Using OW plus Red LEDs



Dimming to Warmer White

2700K

2200K



Benefits of Hybrid WW LED in One Package

Compact LED engine by reducing footprint

More suitable for spot lighting

Cost reduction

Better color uniformity


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sun development 2012rdworkshop

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