Gallium Nitride Blue Lasers - IEE · The Race for GaN Blue Lasers Scott Corzine 1 The Race for...

Scott Corzine

Scott Corzine The Race for GaN Blue Lasers 1

The Race for Gallium Nitride

Blue Lasers:

Scott Corzine October 24, 2014

A Tribute to Shuji Nakamura

Scott Corzine


Outline

• Motivation

• Challenges

• Accomplishments

• What’s Happened

Recently

Scott Corzine


Key Markets for Blue Lasers

DVDs Laser Printers Color Displays

Requirements:

Good Beam Quality

Read: 1-2 mW

Write: 15-30 mW 5-10 mW 1-10 W

Advantages:

3-Fold Increase in

Storage Density

Lower NA allows

Simpler Optics

Efficient, Compact, High

Power Blue Light Source

High Efficiency

410 nm or less 450 nm, 520 nm

Scott Corzine


Basic Components of a Semiconductor Laser

Substrate

Epi Layers • P Cladding • I Active • N Cladding

• Lateral Processing

• Mirror Facets

Optical Cavity

Electrical Connection

• P Contact

• N Contact

Scott Corzine


Epi Material Requirements

• Active Layer: direct bandgap semiconductor

in the desired wavelength range

• Cladding Layers: compatible higher-bandgap

semiconductors – large bandgap differences to confine electrons

– large index differences to confine photons

• Substrate: must be suitable for epitaxial growth – lattice-matched to desired epi materials

– compatible crystal structure (zinc blende, wurtzite, etc.)

Scott Corzine










Scott Corzine


He

Ne

Ar

Kr

Xe

Rn

F

Cl

Br

I

At

O

S

Se

Te

Po

N

P

As

Sb

Bi

C

Si

Ge

Sn

Pb

B

Al

Ga

In

Tl

Zn

Cd

Hg

Cu

Ag

Au

2

10

18

36

54

86

9

17

35

53

85

8

16

34

52

84

7

15

33

51

83

6

14

32

50

82

5

13

31

49

81

30

48

80

29

47

80

VII VI V IV III

II

I

VIII

• • •

Periodic Table

• S

ma

ller

Ato

m

• S

ma

ller

La

ttic

e C

on

sta

nt

• S

ho

rte

r W

ave

len

gth

Scott Corzine


III-V and II-VI Compounds

BN

BP

BAs

BSb

AlN

AlP

AlAs

AlSb

GaN

GaP

GaAs

GaSb

InN

InP

InAs

InSb

III-V Materials

II-VI Materials

HgO

HgS

HgSe

HgTe

ZnO

ZnS

ZnSe

ZnTe

CdO

CdS

CdSe

CdTe

MgO

MgS

MgSe

MgTe

Short

Wavelength

Long

Wavelength

Scott Corzine


400 600 800 1000 1200 1400 1600 1800

Lasing Wavelengths of Common Semiconductor Materials

InP

AlGaAs

InGaP 620-690 nm

700-1100 nm

1200-1600 nm

• Telecom, Datacom

Wavelength (nm)

InGaAs InGaAsP InP

InGaAs GaAs AlGaAs

InGaP AlInGaP AlInP

• DVDs, Laser Printers

• CDs, Laser Printers, Datacom

Scott Corzine


350 400 450 500 550 600 650

Different Options for Blue Lasers

2f-GaAs

ZnSe

GaN 390-440 nm

480-550 nm

400-500 nm

• Bulky, Complex External Optics

Wavelength (nm)

InGaAs GaAs AlGaAs

ZnCdSe ZnSSe ZnMgSSe

InGaN GaN AlGaN

• Lattice-Mismatched System

• Short Lifetimes (<1000 hrs)

• Not Blue Enough

InN GaN

Scott Corzine










Scott Corzine


Role of Cladding Layers

P

N

ΔEc

e–

h+

Δn

active

ba

rrie

r

cla

dd

ing

index profile

mode profile

Ileak ~ exp[-ΔEc /kT ]

Electron Confinement

Optical Confinement

want large ΔEc

• smaller Ith

• better over T

want large Δn

• maximize Γ

• reduce substrate leakage

Γ = energy in active

total energy

Scott Corzine


Common Lattice-Matched Systems

AlAs

GaAs

InP

InAs

AlP

GaP

AlGaAs

InGaAsP

AlInGaP

0

0.5

1

1.5

2

2.5

5.4 5.5 5.6 5.7 5.8 5.9 6 6.1

Ban

dgap

(eV

)

Lattice Constant (Å)

Scott Corzine


AlInGaN Material System

GaN

InN

AlN

?

1

2

3

4

5

6

7

3 3.1 3.2 3.3 3.4 3.5 3.6

-4 -2 0 2 4 6 8 10 12B

and

gap

(eV

)


Strain (%)

Lattice mismatch limits:

• Al and In compositions

• Epi layer thickness

InGaN (In < ~20%)

AlGaN (Al < ~20%)

Scott Corzine


Conduction Band Offsets ΔEc Material

GaAs/AlAs

InGaAsP/InP (1.55µm)


InGaP/AlInP

InGaN/GaN (xIn=10%)

InGaN/GaN (xIn=20%)

GaN/AlGaN (xAl=10%)

GaN/AlGaN (xAl=20%)

440 meV

220 meV

160 meV

260 meV

100 meV

200 meV

100 meV

200 meV

(estimates do not take into account strain and quantum effects) (GaN numbers assume 50% conduction band offset)

Scott Corzine


One Method to Reduce Leakage

P N

active

ba

rrie

r

cla

dd

ing

active

ba

rrie

r

cla

dd

ing

e– e– P N

Electron

Blocking Layer

After

Shuji Nakamura

P-AlGaN (x=0.05) 5000 Å

P-GaN 1000 Å

AlGaN (x=0.2) 200 Å

InGaN(x=0.2) MQW 360 Å

N-GaN 1000 Å

N-AlGaN (x=0.05) 5000 Å

Example

Epi Design

Scott Corzine


Index Differences Δn Material

GaAs/AlAs



InGaP/AlInP

GaN/AlGaN (xAl=10%)

GaN/AlGaN (xAl=20%)

GaN/AlN

0.6

0.4

0.3

0.4

0.06

0.12

0.44

AlxGa1-xN index @ 400nm, x < 0.3 ~ 2.54 - 0.6x

(from Brunner et. al., JAP, 82 (10), p5090, 1997)

Scott Corzine


0

0.001

0.002

0.003

0.004

0.005

2.46

2.5

2.54

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6

Mod

e S

hap

e (G

/nm

)In

dex

Pro

file

z (mm)

GaN AlGaN AlGaN

x = 0.05

x = 0.1

x = 0.15

Typical Cladding:

x = 0.07-0.1

d = 0.4-0.6 mm

l= 410 nm

GaN/AlGaN Waveguide Modes: Effect of Cladding Composition

Guide =

0.25µm

Scott Corzine










Scott Corzine


Common Material Systems

AlAs

GaAs

InP

InAs

AlP

GaP

AlGaAs

InGaAsP

AlInGaP

GaAs Substrate

InP Substrate

0

0.5

1

1.5

2

2.5

5.4 5.5 5.6 5.7 5.8 5.9 6 6.1

Ban

dgap

(eV

)


Scott Corzine


1

2

3

4

5

6

7

2.6 2.8 3 3.2 3.4 3.6

-15 -10 -5 0 5 10B

and

gap

(eV

)


Strain (%)

Substrate Options for GaN

GaN

InN Sapphire SiC

AlN Buffer Layer

Required

Scott Corzine


GaN on Sapphire

Carrier Recombination,

Scattering, Reliability?

Sapphire

Substrate

GaN or AlN

Buffer Layer

(Low Temp)

GaN

(High Temp)

Dislocation Density

~ 109 - 1010 cm-2 TEM image from

D. Basile, HP Labs

Scott Corzine


SiC vs Sapphire GaN Laser on SiC

• Conductive Substrate Allows:

Vertical Current Flow

Single Top Contact

• 10x Better Thermal Conductivity

• High Quality Cleaved Facets

• But, Substrates are Expensive

GaN Laser on Sapphire

• Insulating Substrate Requires:

Two Top Contacts

• Poor Thermal Conductivity

• Poor Cleaved Facets

• But, Best Devices Still Made

on Cheap Sapphire Substrates

Scott Corzine


Cavity Requirements

• Vertical Waveguiding: large index differences

• Lateral Waveguiding: must be able to process

the epi materials – gain-guided (metal patterning)

– stripe and ridge waveguides (etching)

• Low Scattering Losses: smooth surfaces/interfaces

• Optical Feedback: crystal facets or distributed

reflectors – smooth cleaved facets

– smooth etched facets

– etched periodic gratings (regrowth)

Scott Corzine


Cavity Requirements










Scott Corzine


Types of Lateral Guides

Gain-Guided Stripe Ridge

Metal Stripe

• No Etching

Simple to Make

• Poor Confinement

High Threshold

Low Efficiency

Deep Mesa etched

past Active

• Good Confinement

Low Threshold

Multi-Mode

• Poor Heat Flow

Shallow Mesa etched

into Upper Cladding

• Controlled Confinement

Low Threshold

Single-Mode

• Good Heat Flow

Scott Corzine


Sidewall Etching Examples

Youtsey, et al. Appl. Phys. Lett. 71, 2151 (1997)

Dry Etching Using

Cl2/H2/Ar ICP (~ 0.7 µm/min)

2 µm 2 µm

Shul, et al. Appl. Phys. Lett. 69, 1119 (1996)

Wet (PEC) Etching Using

KOH under UV light (~ 0.3 µm/min)

Scott Corzine


Nakamura, et al. Appl. Phys. Lett. 73, 832 (1998)

Ridge Laser for Single-Mode

Mesa Height and Width Control

Lateral Mode Structure typical width ~ 3-5µm

Etched Mesa Effective Index Step

Current Confinement active guide

guide cladding

cladding contact

contact

neff2 neff2 neff1

2 µm

Etched sidewalls can be

a source of scattering

70 mW

100 mW

3 µm

Scott Corzine


Cavity Requirements










Scott Corzine


Cavity Loss Mechanisms

L

Internal Losses: •Absorption

• Scattering

Mirror Losses

xieP

~

Internal Loss

)(cm -1

i

RLm

1ln

1

Scott Corzine


Internal Cavity Losses i Material

GaAs/AlAs

InGaAsP/InP

InGaN/AlGaN

35-50 cm-1

3-10 cm-1

Sources of Internal Loss

• Absorption

Free Carriers in Doped Layers

Absorption Tails in “Transparent” Layers

• Scattering

Dislocations

Rough Sidewalls

Scott Corzine


Measured AlGaN Absorption Curves

Brunner, et al. J. Appl. Phys. 82, 5090 (1997)

Large

Absorption Tails

Scott Corzine


Cavity Requirements










Scott Corzine


Cleaving GaN on Sapphire

m-face Cleavage Planes

of Sapphire

Sapphire

GaN

~2.4° 3 µm

)1021(

)0011(

Stocker, et al. Appl. Phys. Lett. 73, 1925 (1998)

16 nm roughness

R ~ 4%

Scott Corzine


Cleaving GaN on SiC

1 µm

High Quality

Cleaved Facets

Are Readily

Obtained

Doverspike, et al. SPIE ’98, 3284, 82 (1998)

Scott Corzine


Other Types of Mirrors

Dry-Etched Facets 3rd-Order Gratings

Hofstetter, et al. Appl. Phys. Lett. 73, 2158 (1998)

Abare, et al. Appl. Phys. Lett. 73, 3887 (1998)

Scott Corzine


Performance Requirements

• High Optical Gain: small effective masses – low threshold current

– high differential gain

• High P- and N-Doping: shallow donor and

acceptor levels – low voltage operation

• low series resistance

• good ohmic contacts

• Robust, Reliable Materials: low impurity and

defect concentrations – long lifetime

Scott Corzine











Scott Corzine


Relevant Gain Parameters

Material

GaAs/AlAs

InGaAsP/InP

InGaN/AlGaN

~1019

1-2 x 1018

mC

0.15-0.2

0.04-0.07

mHH

0.8-1.6

0.35-0.6

tr (ns) Material

GaAs/AlAs

InGaAsP/InP

InGaN/AlGaN

2-3

2-3

Jtr (A/cm2)

200-500

50-100

Ntr (cm-3)

Large Effective Masses Takes Lots of

Carriers to Get Gain

dg/dN (cm2)

0.5-2 x 10-16

2-5 x 10-16

Scott Corzine


Gain vs Current Density (Theory)

Example Design:

If R = 18%, L= 500µm

m ~ 35 cm-1

Yeo, et al. J. Appl. Phys. 84, 1813 (1998) Current Density (kA/cm2)

Modal

Gai

n, G

g (

cm-1

)

1 0.5 1.5 2 2.5 3 0

nw = 1

nw = 2

nw = 3

nw = 4

0

20

40

60

80

100

120

140

(50Å)

In0.2Ga0.8N/GaN MQW

If i = 0 cm-1

Jth ~ 1 kA/cm2

nw ~ 1 or 2

If i = 40 cm-1

Jth ~ 2 kA/cm2

nw ~ 2, 3, or 4

Scott Corzine


Other Issues for Gain in InGaN QWs

Very Unusual:

Broad Low Energy Gain Spectrum

Song, et al. Appl. Phys. Lett. 72, 1418 (1998)

• Indium Clustering? – localized transitions?

– quantum dot effects?

• Free Electron-Hole Pair or

Exciton Transitions?

• Piezoelectric Field is Strong

in Strained InGaN – is gain affected?

Scott Corzine











Scott Corzine


Voltage Drops in Laser Structure

Rn-contact Rn-AlGaN/GaN

Rspread (n-GaN)

Vlaser = Vdiode + I ( R)

GaN

AlGaN

Metal

Active

Rp-contact

Rp-AlGaN/GaN

Scott Corzine


Dopant Materials P-Type Dopants Material

GaAs

GaN

AlGaN

Si 5.8 ~3x1018

Se 5.8 ~1019

Si 12-17 ~1019

Si 15-20 ~1019

N-Type Dopants

Element Eact (meV) Cmax (cm-3)

C 26 ~1020

Zn 30.7 ~1019

Mg 28.4 ~1019

Be 28 ~1019

Mg 170-200 ~1018

Mg + 4·x[%] ~1017

Element Eact (meV) Cmax (cm-3)

r (p-GaN) ~ 1-2 Wcm 0.1-0.2 V/µm @ 1 kA/cm2

r (p-AlGaN) ~ 10-20 Wcm 1-2 V/µm @ 1 kA/cm2

r (n-GaN/AlGaN) < 0.01 Wcm

Scott Corzine


Ohmic Contacts

P-Contacts Material

GaAs

GaN

N-Contacts

Metal rc (W-cm2)

AuZn 10-5-10-6

Ni/Au 10-2-10-3

Pt/Ni/Au 5x10-4

Pd/Au 4x10-4

Ta/Ti 3x10-5

Au/Ge/Ni 10-5-10-6

Ti/Al 10-5-10-6

Pd/Al 10-5

Ti/Ag 5x10-5

Ti/TiN 4x10-6

Metal rc (W-cm2)

rc = 10-3 W-cm2 1 V @ 1 kA/cm2

recently

reported

Want rc < 10- 4 W-cm2

Scott Corzine


Example: Voltage Drops @ 10kA/cm2

0.1 Wcm (0.5µm)

0.05V

Vlaser = 3V + 16.15V

~ 19V

GaN

AlGaN

Metal

Active

10-3 W-cm2 10V

10 Wcm (0.5µm)

5V

10-5 W-cm2 0.1V

0.01 Wcm (100µm) 1V (assuming conduction x-section comparable

to laser stripe dimensions)

(assuming current crowding comparable

to laser stripe width)

Scott Corzine











Scott Corzine


Degradation Mechanisms Material

AlGaAs

GaN

• Oxygen Contamination is a Source of

Nonradiative Recombination which can

Limit Device Lifetimes

• Laser Facet Damage

• High Dislocation Densities are a Major

Concern. However:

(1) Defect Propagation is Slower than in GaAs (but more temperature dependent)

(2) Defect Recombination Rates are Slow

• Laser Facet Damage?

Reliability Issues

For Long Lifetime, Still Desirable to Minimize Defect Density

Scott Corzine


Epitaxial Lateral Overgrowth (ELOG)

Vertical Dislocation Threads

Can’t Follow Lateral

Growth

Nam, et al. Appl. Phys. Lett. 71, 2638 (1997)

Lateral

Growth

The Result:

Nearly Defect-Free Material!

Scott Corzine


Highlights of Challenges for GaN Laser Research

• Lattice Mismatched System – limits range of cladding layer compositions and thicknesses

– difficult to create good electron and photon confinement

• Lack of Suitable Substrate – high dislocation densities

• reliability concerns

• large scattering losses

– high quality cleaved facets are difficult to make

• Large Effective Masses (in Both Conduction and Valence Bands)

– high carrier and current densities required for optical gain

– low differential gain (due to asymmetry in band structure)

• Large Acceptor Activation Energy – high p-type doping difficult (especially in AlGaN)

• high series resistance

• hard to make good p-ohmic contacts

– high voltage operation

Scott Corzine


First GaN Blue Laser - Dec‘95

(Nichia)

Nakamura, et al. Jpn. J. Appl. Phys., 35, L74 (1996)

1μs pulse width

1ms rep rate

Scott Corzine


Nichia’s Early Laser Structure

c-face Sapphire

Substrate

RIE-Etched

Facets

InGaN MQW

Active

Ridge Waveguide

Nakamura, et al. IEEE J. STQE, 3, 712 (1997)


Scott Corzine


Who’s Got Blue? (circa 1998) Operation Company

Nichia

Meijo University

Toshiba

Cree

Fujitsu

UCSB

Sony

Xerox

Hewlett Packard

SDL

Pioneer

RT, CW: 6000 hr

RT, Pulsed

RT, Pulsed

RT, quasi-CW: 30 sec

250K, quasi-CW: 1 sec

RT, Pulsed

RT, quasi-CW: 1 sec

RT, Pulsed

RT, Pulsed

RT, Pulsed

RT, Pulsed

RT = Room Temperature

CW = Continuous Wave

Entry Date (CW)

Dec-95 (Nov-96)

Jun-96

Sep-96

Jun-97 (Jan-98)

Jul-97 (Oct-98)

Sep-97

Oct-97 (Jul-98)

Oct-97

Nov-97

Feb-98

Aug-98

Scott Corzine


Typical Commercial Laser Performance

CD Players, DVD Players, Laser Printers

Threshold Current, Ith :

Threshold Voltage, Vth :

Output Power, Pout :

20-50 mA

2-3 V

5-30 mW

0.1-1 mA

1.6-2 V

1-2 W

High Performance/Specialty Applications

Threshold Current, Ith :

Threshold Voltage, Vth :

Output Power, Pout :

Scott Corzine


0

500

1000

1500

2000

0

2

4

6

8

10

12

14

16

Ith (mA)

Jth (kA/cm2)

Th

resh

old

Cu

rren

t (m

A)

Jth (k

A/cm

2)

CW

1996 1997 1998

Nichia’s Amazing Progress

16 mA!

1.2 kA/cm2

Nichia

Scott Corzine


Nichia’s Blue Laser (circa 1998)

• l : ~ 410 nm

• Ith : ~ 50 mA

• Jth : 3-5 kA/cm2

• Vth : ~ 5 V

• Pout : > 30 mW

CW


Scott Corzine


0

200

400

600

800

1000

1200

1400

1600

0

2

4

6

8

10

12

14

16

Th

resh

old

Cu

rren

t (m

A)

Jth (k

A/cm

2)

1997 1998

= CW

Other “quasi-CW” Players

Cree

Sony Fujitsu

CW lifetimes all < 1 min

Scott Corzine


Cree’s Blue Laser (circa 1998) Pulsed

CW • SiC Substrate

• Stripe Waveguide

• Cleaved Facets

• Wavelength : 408 nm 425 nm

• Lowest Ith : 107 mA 600 mA

• Lowest Jth : 7.1 kA/cm2 25 kA/cm2

• Lowest Vth : 15.7 V 25 V

• Pmax : 2.4 mW 1.2 mW

Pulsed CW

Doverspike, et al. SPIE ‘98, 3284, 82 (1998)

Bulman, et al. LEOS ‘98, FI2 (1998)

Scott Corzine


Fujitsu’s Blue Laser (circa 1998) Pulsed

CW



• Lowest Jth : 9.5 kA/cm2 12 kA/cm2

• Lowest Vth : 12.5 V 12.6 V

• Pmax : > 20 mW > 0.2 mW

• SiC Substrate

• Ridge Waveguide

• Cleaved Facets

Pulsed CW

Soejima, et al. Jpn. J. Appl. Phys., 37, L1205 (1998)

Scott Corzine


UCSB’s Blue Laser (circa 1998)

• c-face & a-face Sapphire Substrate

• Gain-Guided Waveguide

• RIE-Etched & Cleaved Facets

Pulsed

• Wavelength : 422 nm

• Lowest Ith : 650 mA

• Lowest Jth : 9.2 kA/cm2

• Lowest Vth : 19 V

• Pmax : 67 mW

Pulsed

A.C. Abare, M.P. Mack, et al. IEEE JSTQE, 4, 505 (1998)

Scott Corzine


Sony’s Blue Laser (circa 1998) Pulsed CW

• c-face Sapphire Substrate

• Ridge Waveguide

• Cleaved Facets



• Lowest Jth : 7 kA/cm2 11.7 kA/cm2

• Lowest Vth : 11.8 V 11.5 V

• Pmax : > 5 mW > 5 mW

Pulsed CW

Kobayashi, et al. Electron. Lett., 34, 1494 (1998)

Scott Corzine


Xerox’s Blue Laser (circa 1998)


• Gain-Guided Waveguide

• CAIBE-Etched Facets

Pulsed



• Lowest Jth : 20 kA/cm2


• Pmax : ~ 50 mW

Pulsed

David P. Bour, et al. IEEE JSTQE, 4, 498 (1998)

Scott Corzine


0

10

20

30

40

50

0 0.2 0.4 0.6 0.8 1

Current (A)

Forw

ard

Volt

age (

V)

0

20

40

60

80

100

Lig

ht

Ou

tpu

t p

er f

acet

(mW

)

HP’s Blue Laser (circa 1998)

p-contact (Ni/Au)

p-GaN

p-AlGaN

p-GaN QW(n-GaInN/n-GaInN)

n-GaN

n-AlGaN n-GaN

Buffer(AlN)

Sapphire (0001)

n-contact (Ti/Al)

RIE etched wall

Cleaved facet


• Ridge Waveguide

• Cleaved Facets

Pulsed



• Lowest Jth : 16 kA/cm2


• Pmax : ~ 100 mW

Pulsed

Scott Corzine


0.0001

0.001

0.01

0.1

1

10

100

1000

104

0

5

10

15

20

25

30

35

40

RT

-CW

Lif

etim

e (h

ou

rs) T

hresh

old

Vo

ltage (V

)

1996 1997 1998

Nichia’s Amazing Progress II

V Drop

CW

stripe

LD

ridge

LD

c-face

sapph

thick

ELOG

extrapolates to

> 10 kHrs!

Si-doping

in MQW

MD-SLS

cladding

&

Scott Corzine


Nichia RT-CW Lifetime Data

> 6000 Hrs

Lifetime

Nakamura, et al. Science, 281, 956 (1998)

Scott Corzine


Evolution of Nichia’s Substrate

• Free Standing GaN Substrate

+

• ELOG with Thick Buffer • Sapphire Substrate

Polished

Off

LT Buffer

ELOG + Sapphire Removal

10-20µm

80-150µm

c-face

“Defect-Free” Regions

Epi Layers

80µm LP-MOCVD

or

150µm HVPE

Scott Corzine


0

100

200

300

400

500

0

10

20

30

40

50

CW

Po

wer

/Fac

et (

mW

)Q

uan

tum

Efficien

cy (%

)

1997 1998

Nichia’s Amazing Progress III

RIE etched

mirrors

cleaved

facets

420 mW!

ELOG sub

“GaN” sub

uncoated/HR

stripe widths = 3 or 4 µm

in all cases

AP

growth

LP

growth

Scott Corzine


Nichia High Power Blue Laser

420 mW with

11% WP Eff.


Scott Corzine


Summary of Best Results (circa 1998)

Ith (mA) Company

Nichia

Cree

Sony

Fujitsu

Toshiba

Xerox

HP

SDL

Pioneer

Meijo

UCSB

16

600

466

380

(P and are per facet)

Vth (V)

4.3

15.7

11.5

12.5

20

16

14

35

16

19

107

280

300

530

600

300

820

290

650

CW Pulsed

Jth (kA/cm2)

1.2

25

11.7

12

7.1

7

9.5

10.6

16

16

8.5

41

2.9

9.2

CW Pulsed

P (mW)

420

1.2

5

0.2

ext (%)

8

49

20

0.7

5

4.2

235

280

80

50

100

150

35

67

39

0.3

CW Pulsed CW Pulsed

Lifetime

6000 hrs

30 sec

1 sec

1 sec

RT-CW

Scott Corzine


Date Wed, 13 Jan 1999 103425 +1728

From shuji NAKAMURA <[email protected]>

Subject commercialization of violet laser diodes

Announcement of a start of sample shipments of InGaN-based

violet laser diodes

We announced a commercilization of first InGaN-based violet

laser diodes through Japanese Nikkei Sangyo news paper

yesterday on January 12, 1999. The charactersistics of the

violet laser diodes are an output power of 5 mW, an emission

wavelength of 400 nm, an operating current of 40 mA and an

operating voltage of 5V. The lifetime of the laser diodes is

more than10,000 hours at room temperature. If you were

interested in testing our laser diodes, please check URL

http//www1a.mesh.ne.jp/nichia/index-e.htm. Just for your

information.

Sincerely yours,

Shuji Nakamura

-----------------------------

Shuji Nakamura

R & D Department

Nichia Chemical Industries Ltd.

491, Oka, Kaminaka, Anan

Tokushima 774, Japan

Phone +81-884-23-7787

Fax +81-884-23-1802

e-mail (Office) [email protected]

------------------------------

Nichia Announces Commercial Sampling of

Blue Laser Diodes - Jan 12, 1999 E-mail sent out

by Nakamura: Nichia’s Web Page:

]

V I O L E T L A S E R D I O D E

N i c h i a a n n o u n c e s t o r e l e a s e s a m p l e s h i p m e n t o f V I O L E T L A S E R D I O D E .

S P E C I F I C A T I O N

T y p e N o . N L H V 5 0 0

W a v e L e n g t h 4 0 0 ( n m )

O u t p u t P o w e r 5 ( m W )

P a c k a g e s i z e & p h i ; 5 . 6 c a n t y p e

C O N T A C T

T O K Y O T E C H N I C A L C E N T E R N I C H I A C H E M I C A L I N D U S T R I E S , L T D .

T E L : + 8 1 - 3 - 3 4 5 6 - 3 7 4 6 F A X : + 8 1 - 3 - 5 4 4 0 - 7 5 1 6 E - m a i l : h s h i m i z u @ t o k y o . n i c h i a . c o . j p

[ H O M E ] [ C O M P A N Y P R O F I L E ] [ H I G H B R I G H T N E S S L E D s ] [ U L T R A G L O W ] [ I R V I C O N ] [ R E F E R E N C E

C o p y r i g h t © 1 9 9 8 , 1 9 9 9 N i c h i a C h e m i c a l I n d u s t r i e s , L t d .

Scott Corzine


Fast-Forward 5 Years… Sony At Photonics West 2004:

Scott Corzine


Progress in the U.S.

Xerox Blue Laser in 2001

M. Kneissl et al., IEEE Jour. Sel. Topics in Quantum Electronics 7, 188 (2001).

Scott Corzine


DVD Market

“Blu-ray Disc” Standard

27GB

12 cm disc

single-sided

single-layer

(conventional DVDs = 4.7GB)

Scott Corzine


What Happened to Nakamura?

January 30, 2004…the Japanese court ruled in favor of Nakamura

over Nichia in a lawsuit quoting that:

Scott Corzine


Fast-Forward 10 Years…

Scott Corzine


Shuji wins the Nobel Prize in 2014…

http://www.nobelprize.org/nobel_prizes/physics/laureates/2014/nakamura-interview.html

Scott Corzine

Scott Corzine The Race for GaN Blue Lasers

Isamu Akasaki

Hiroshi Amano

Shuji Nakamura

77

share the Nobel Prize

Scott Corzine


Tetsuya Takeuchi Part of Agilent Labs Blue Laser Team (led by Rick Schneider)

Now a Professor at Meijo University

In 1973, Professor Akasaki embarked upon the

previously unexplored challenge of using nitride

semiconductors to create a p-n junction-type high-

performance blue luminescent device.

However, the issues were even more difficult than

predicted, resulting in many challenges and

setbacks. In the last half of the 1970s, many

researchers abandoned the "unexplored

semiconductor" research.

Feeling like he was "walking alone in a

wasteland", Professor Akasaki worked on gallium

nitride (GaN) crystal growth day and night.

One day, he saw a tiny crystal under his

fluorescent microscope that gave off cobalt blue

light, and became convinced of the major

possibilities of GaN.

Isamu Akasaki

Scott Corzine


I joined Professor Isamu Akasaki's group

in 1982 as an undergraduate student.

In 1985, I developed low-temperature

deposited buffer layers for the growth of

group III nitride semiconductor films on

a sapphire substrate, which led to the

realization of group-III-nitride

semiconductor based light-emitting

diodes and laser diodes.

In 1989, I succeeded in growing p-type

GaN and fabricating a p-n-junction-type

GaN-based UV/blue light-emitting diode

for the first time in the world.

Hiroshi Amano

Scott Corzine


“It also makes me happy to see that my

dream of LED lighting has become a

reality,” Nakamura said in a statement a

press conference this morning.

Nakamura also said he did not

anticipate developing the blue LED

from the outset of his research but

rather started with the goal of simply

getting a Ph.D.

“My dream was to get a Ph.D. At that

time, in Japan, by submitting several

scientific papers, you can get a Ph.D…

you don’t have to go to university … so

at the time, my dream was to publish

five scientific papers, not blue LED,”

Nakamura said.

Shuji Nakamura

Gallium Nitride Blue Lasers - IEE · The Race for GaN Blue Lasers Scott Corzine 1 The Race for...

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