recent developments on uv emitting phosphors · 1. application areas of uv radiation photochemistry...

Recent Developments onRecent Developments on UV Emitting Phosphors

Thomas Jüstel

[email protected]://www.fh-muenster.de/fb1/personal/professoren/juestel/Juestel.phphttps://www.fh muenster.de/fb1/personal/professoren/juestel/Juestel.php

8th Phosphor Global SummitSan Diego, CA

Prof. Dr. T. Jüstel, University of Applied Sciences Münster, Germany Slide 1

g ,March 25th, 2010

OutlineOutline

1 Application Areas of UV Radiation1. Application Areas of UV Radiation

2. UV Radiation Sources

3. UV Emitting Phosphors

4. Efficiency of UV Emitting Phosphors

5 Thermal Q enching and VUV Stabilit5. Thermal Quenching and VUV Stability

6. Conclusions and Future Trends


1. Application Areas of UV Radiation1. Application Areas of UV Radiation

100 nm 200 nm 280 nm 320 nm 400 nm

UV-B UV-AUV-CVUV

100 nm 200 nm 280 nm 320 nm 400 nm12.5 - 6.9 eV 6.2 – 4.5 eV 4.5 - 3.9 eV 3.9 – 3.1 eV

Cleavage of H2O and O2i t di l

Excitation of C=C bonds Vitamine D3 production Photocatalytic reactionsinto radicals

Ozone formation

Cleavage of C C C H C O

Excitation of nucleobasesand tryptophane

Transcription of repairenzymes

M l f ti

Melanine oxidation(skin)

Cleavage of C-C, C-H, C-O bonds

Cleavage of O3, ClO2 and H2O2

Conversion of NO3- to NO2

-

Melanosome formation(skin)

Decomposition of organic pigments

Activation of h t t l ti l i tphotocatalytical pigments

• Waver cleaning

• Photochemistry

• Disinfection of air, H2O and surfaces

• Treatment of skindiseases, e.g. psoriasis

• Water and air purification@ TiO2 photocatalyst, formation of OH. and O2

.

radicals• Photochemistry • Tanning

• Photochemistry

radicals

• Tanning

Photochemistry


• Photochemistry

1. Application Areas of UV Radiation1. Application Areas of UV RadiationPhotochemistry - Water on air components1. Photochemical cleavage of waterH2O + h(< 200 nm) OH. + H.

2 OH. H2O22 H2O2 2 H2O +1O2

2. Ozone formationO2 + h(< 200 nm) 2 O.

2 O2 + 2 O. 2 O3

3. Photochemical cleavage of ozoneO3 + h(< 320 nm) O2 + 1O

4. Photochemical cleavage of carbon dioxidegCO2 + h(< 200 nm) CO + O.

5. Cleavage of N2 and subsequent NO formation

240 nm


5. Cleavage of N2 and subsequent NO formationN2 + h(< 120 nm) 2 N. 2 N + O2 2 NO

1. Application Areas of UV RadiationPhotochemistry - Effect on O3 and H2O2

1. Application Areas of UV Radiation

1. Cleavage of OzoneO3 + H2O + h(< 330 nm) H2O2 + O2

O3 + h(< 300 nm) O2 + O.

O. + H2O 2 OH.

2. Cleavage of Hydrogen PeroxideH O + h (< 280 ) 2 OHH2O2 + h(< 280 nm) 2 OH.

OH. radicals are the key to Advanced Oxidation Processes (AOPs)OH. + M OH- + M+

Decomposition of organic compounds in air water and @ surfaces


Decomposition of organic compounds in air, water and @ surfaces

1. Application Areas of UV RadiationPhotochemistry – Electrocyclic reactions

[2 2] l dditi ibl f DNA d di i f ti

1. Application Areas of UV Radiation

e.g. [2+2] cycloaddition → responsible for DNA damage → disinfection

1,0 Disinfection efficiency (DIn 5031-10)

n

2s + 2s

OCN

NCO

O HP0,6

0,8

Absorption spectrum of dTMP

cien

cy/a

bsor

ptio

n

CCCH3H

PO

NCO H

0,2

0,4

Rel

. effi

cNucleotide at 260 nm

P

CCCN

NC O

CH3HO

OCC

CNNC O

H

200 250 300 3500,0

Wavelength [nm]

dAMP 15200 lmol-1cm-1

dTMP 8400 lmol-1cm-1

dGMP 12000 lmol-1cm-1P

OCN

NCO

O H

CCCH3H


dCMP 7100 lmol-1cm-1CCCH3H

1. Application Areas of UV Radiation1. Application Areas of UV Radiation21st Century Challenge: Air, Soil, and Water Pollution

6000 AgricultureI d

5000

IndustryHouseholdTotal

n / 1

09m

3

4000

onsu

mpt

ion

3000

• UV-C Radiation (260 nm) inactivates micro- Wat

er c

o

2000

organisms due to DNA photochemistry• VUV Radiation (180 nm) oxidizes due to

H2O cleavage and OH. And O2.- formation

Industrial installations → discharge lamps

1000


Industrial installations → discharge lampsMobile devices → discharge lamps / diodes 0

1900 1950 2000 2050Year

2. Types of UV Radiation SourcesSun > 300 nm

Hg discharge lamps

2. Types of UV Radiation Sources1,0 UV-AUV-B

m-1]

Solar UV spectrum

Hg discharge lamps• low pressure 185, 254 nm• amalgam 185, 254 nm• medium pressure 200 – 400 nm 0,4

0,6

0,8

al ir

radi

ance

[Wm

-2n

p

Xe/(Hg) discharge lamps 230 – 800 nm

D discharge lamps 110 400 nm280 300 320 340 360 380 400

0,0

0,2

Spe

ctra

Wavelength [nm]

Solar radiationat 60° sun height(clear sky)

D2 discharge lamps 110 – 400 nm

Excimer LASER• ArF* 193 nm

Medium pressure Hg lamps

1,0

1,2

y

Excimer lamps• Xe2* 172 nm• KrCl* 222 nm 0 4

0,6

0,8

mal

ised

Inte

nsity

• KrCl 222 nm• XeBr* 282 nm• XeCl* 308 nm

200 220 240 260 280 300 320 3400,0

0,2

0,4

Nor

m

Wavelength [nm]


(Al,Ga)N LEDs 210 – 370 nm

2. Types of UV Radiation Sources

147 172150

2. Types of UV Radiation SourcesPhilips Patent

DE 199 19 169 7

Desired lampspectrum

147 172Resonance

Intensity

1stC

ontinu

150

2ndC

ontin

DE 199 19 169.7

spectrum

Wavelength [nm]

e Line

y[a.u.]

uum

nuum

Features

(quartz) glassWavelength [nm]

Application areas Phosphor layer

Phosphor layer

Features– Discharge efficiency ~ 65%

(elaborated driving scheme)– Hg free

Application areas Phosphor layer– Plasma displays RGB– Copier lamps RGB or B/W– LCD Backlighting RGBg

– Fast switching cycles– Temperature independent– Dimmable

LCD Backlighting RGB– Medical skin treatment UV-A/ or UV-B– Disinfection UV-C– Ultra pure water VUV


– Main emission band at 172 nm (VUV)p

– Surface/wafer cleaning VUV

3. UV Emitting Phosphors3. UV Emitting PhosphorsHost lattices and activators ions

100 nm 200 nm 280 nm 320 nm 400 nm

UV-B UV-AUV-CVUV

Host lattices

Fluorides Phosphates Borates Silicates Aluminates

Activator ions

Nd3+NdPb2+, Pr3+, Bi3+

Gd3+, Bi3+, Pr3+, Ce3+

Tm3+ , Pb2+, Ce3+


Tm , Pb , Ce

3. UV Emitting Phosphors1S0 – 2S+1LJ line emissionYF3:Pr NaYF4:Pr

Pr3+ - Tuning its emission spectrum3. UV Emitting Phosphors

213, 236

EnergyNaYF4:Pr

SrAl12O19:PrLaMgB5O10:PrLaB3O6:Pr

UV band emission

UV li i i

213, 236252, 271407 nm

y of thelow

1S0 – 2S+1LJ line and 4f15d1 – 4f2 band em.KY3F10:Pr 240, 250, 271 nm

4f15d1 4f2 b d i iBlue emission

UV line emission

westcryst

4f15d1 – 4f2 band emissionLiYF4:Pr 218 nmYPO4:Pr 232 nmKYF4:Pr 235 nm

tal-fieldco

YAlO3:Pr 245 nmYBO3:Pr 263 nmLu2Si2O7:Pr 273 nmLu3Al5O12:Pr 310 nm

Red emission

omponent

1D2

Lu3Al5O12:Pr 310 nmY3Al5O12:Pr 320 nm

1D2- 3HJ line emissionY2O3:Pr 615 nm

of [Xe]4f 1


Y2O3:Pr 615 nmCaTIO3:Pr,Na 615 nm

5d1

3. UV Emitting PhosphorsPr3+ doped fluorides: [Xe]4f15d1 – [Xe]4f2 vs. [Xe]4f2 – [Xe]4f2 emission

1,0KY3F10:Pr3+


NaYF4:Pr3+ 252, 271 nm hexagonal CN9KY3F10:Pr3+ 240, 250, 271 nm cubic CN8LiYF4:Pr3+ 218, 228 nm tetragonal CN8 0,6

0,8

[a.u

.]

Emission bei 160 nm Anregung bei 250 nm Reflexion

KYF4:Pr3+ 235 nm hexagonal CN7

0,2

0,4

Inte

nsity

[

200 300 400 500 600 700 8000,0

Wavelength [nm]

1,0KYF4:Pr3+

E i i b i 160

1,0NaYF4:Pr3+

1,0 Excitation spectrum

Em

= 219 nm; Grating 2400 lines/mm

LiYF4:Pr3+

0,6

0,8

ity [a

.u.]


0,6

0,8

ity [a

.u.]


0,6

0,8Em

; gslit size: Ex = 0.50 mm, Em = 4.00 nm

Emission spectrum

Ex= 160 nm; Grating 1200 lines/mm

slit sizes: Ex = 1.50 mm, Em = 0.5 nm

sity

(a.u

.)

0,2

0,4

Inte

ns

0 0

0,2

0,4

Inte

ns

0,0

0,2

0,4

Inte

ns


200 300 400 500 600 700 8000,0

Wavelength [nm]200 300 400 500 600 700 800

0,0

Wavelength [nm]

100 200 300 400 500 600 700 800,

Wavelength [nm]

3. UV Emitting Phosphors3. UV Emitting PhosphorsPr3+ doped garnets: [Xe]4f15d1 – [Xe]4f2 vs. [Xe]4f2 – [Xe]4f2 emission

Emission and excitation spectra of

Lu3Al5O12:Pr3+ Y3Al5O12:Pr3+Lu3Al5O12:Pr Y3Al5O12:Pr

1,0

Emission spectrum Excitation spectrum

160 nm exc.max = 309 nm

1,0 Emission spectrum Excitation spectrum

160 nm excitation

0,6

0,8

nten

sity

centroid = 344 nm

0,6

0,8

nten

sity

0,2

0,4

Rel

ativ

e in

0,2

0,4

Rel

ativ

e i

100 200 300 400 500 600 700 8000,0

0,2

Wavelength [nm]100 200 300 400 500 600 700 800

0,0

0,2

Wavelength [nm]


Wavelength [nm] Wavelength [nm]

3. UV Emitting PhosphorsUV-A Range

Lu3Al5O12:Tm


0,8

1,0 YPO4:CeLaMgAl11O19:CeBaSi2O5:Pb

y

0,8

1,0 Emission spectrum LuAG:Tm 1700°C Excitation spectrum LuAG:Tm 1700°C Reflection spectrum

3 5 12

0,4

0,6

Rel

ativ

e in

tens

it

0,4

0,6

Rel

ativ

e in

tens

ity

150 200 250 300 3500,0

0,2

Sr2MgSi2O7:Pb

R

172 nm100 200 300 400 500 600 700 800

0,0

0,2

R

Standard UV-A phosphorsVUV Efficiency: LaMgAl11O19:Ce > YPO4:Ce ~ BaSi2O5:Pb > Sr2MgSi2O7:Pb


Novel UV-A phosphor for Xe excimer discharge lampsLu3Al5O12:Tm Emission @ 292 and 352 nm, excitation maximum at 170 nm


3 5 12 @ ,LaPO4:Tm and other Tm3+ doped wide band gap hosts show similar em.

spectra

3. UV Emitting Phosphors3. UV Emitting PhosphorsUV-B Range – Gd3+ activated materials

1,0 6P7/2 ->8S7/2

Band gap ~ 172 nmYAl3(BO3)4:10%Gd

160 nm excitation

Sensitisation by the host lattice (suitable band gap!)

Example: YAl3(BO3)4:Gd3+0,6

0,8

7/2 7/2

ve in

tens

ity

Example: YAl3(BO3)4:Gd(NEC patent US2005/001024)

0 0

0,2

0,4

8S7/2->6IJ

Rel

ativ

Sensitisation by co-dopantsBi3+ large lattice site (e.g. La3+) requiredCe3+ suitable 4f5d state pos. required

100 200 300 400 500 600 7000,0

Wavelength [nm]

1,04f2-> 4f15d1

6P 8S

YAl3(BO3)4:10%Gd,1%Pr160 nm excitationp q

Pr3+ suitable 4f5d state pos. requiredNd3+ suitable 4f5d state pos. required

0,6

0,8

6P7/2 ->8S7/2

e in

tens

ity Band gap

Example: YAl3(BO3)4:Gd3+Pr3+

0 0

0,2

0,4

Rel

ativ

e


100 200 300 400 500 600 7000,0

Wavelength [nm]

3. UV Emitting PhosphorsUV-B Range – Gd3+ activated materials


Example: LaMgAl11O19:Gd3+

0,8

1,0 LO NP806 LO TR037-05 LO TR036-05

lues

]

LaMgAl11O19:Gd vs LaPO4:Ce (NP806)

2,0x105

2,2x105

2,4x105 Emission spectrum NP806 Emission spectrum TR3705 Emission spectrum TR3605

LaMgAl11O19:Gd vs LaPO4:Ce (NP806)

unts

)

0 4

0,6

ut [a

bsol

ute

val

1 0x105

1,2x105

1,4x105

1,6x105

1,8x105

n in

tens

ity (C

ou

0,2

0,4

Ligh

t out

pu

exc.slit 2 x 3000 m

emis.slit 2 x 250 mmonitored at 312 nm(LAP C t 320 )

2,0x104

4,0x104

6,0x104

8,0x104

1,0x10

Em

issi

on exc.slit 2 x 3000 memis.slit 2 x 250 mexcitation at 160 nm

Light output at 172 nm close to 100% (20% higher than that of LaPO :Ce)

150 200 250 300 350 4000,0

(LAP:Ce at 320 nm)

Wavelength [nm]

200 250 300 350 4000,0

Wavelength [nm]


Light output at 172 nm close to 100% (20% higher than that of LaPO4:Ce)

3. UV Emitting Phosphors3. UV Emitting PhosphorsUV-B Range – Gd3+ activated Lu3Al5O12 and LnPO4

Lu3Al5O12:Gd3+ GdPO4:Nd3+

1,0

Emission spectrumExcitation spectrum

160 nm exc. 1,0 6P7/2 -8S7/24f3-4f25d1

0 6

0,8

Excitation spectrum

nsity

max

= 311 nm

0 6

0,8

7/2 7/24f 4f 5d

nsity

0,4

0,6

Rel

ativ

e in

ten

0,4

0,6

->6IJ->6GJ

Rel

ativ

e in

ten

100 200 300 400 500 600 700 8000,0

0,2

150 200 250 300 350 400 450 500 550 600 650 700 7500,0

0,2

W l th [ ]

Efficient ET fromthe host lattice to Gd3+


Efficient ET fromNd3+ to Gd3+


3. UV Emitting PhosphorsUV-C Range - Bi3+ or Pb2+ activated materials Ground state config : [Xe]4f145d106s2 Excited state: [Xe]4f145d106s16p1


Ground state config.: [Xe]4f145d106s2 Excited state: [Xe]4f145d106s16p1

1,0 DIN5031-10C SO Pb

1,0 DIN5031-10

0,6

0,8

CaSO4:Pb(Ca,Mg)SO4:PbSrSiO3:Pb

nten

sity

0,6

0,8LuPO4:Bi

inte

nsity

YPO4:Bi

0,2

0,4

Nor

mal

ised

i

0,2

0,4

Nor

mal

ised

200 220 240 260 280 300 320 3400,0

Wavelength [nm]

200 220 240 260 280 300 320 3400,0

Wavelength (nm)

(Ca,Mg)SO4:Pb, SrSiO3:Pb sensitivity towards water, Xe up-take

(Y,Lu)PO4:Bi3+ good chemical stability + high VUV efficiency


3. UV Emitting PhosphorsUV-C Range - Pr3+ activated materials


YPO4:Pr3+ YBO3:Pr3+

1,0 4f2 - 4f15d1 3H4

172 nm1 0

4f15d1 3H4

0,6

0,8

nten

sity

4

3H5

0 6

0,8

1,0

Hostlattice

3H6

3H5

4

0 2

0,4

,

Rel

ativ

e In

3H6 3FJ

Host Lattice

0,4

0,6

3FJ

100 150 200 250 300 350 400

0,0

0,2

Wavelength [nm]100 200 300 400 500

0,0

0,2

Wavelength [nm]

Emission maximum can be tuned between 220 and 320 nm by thet l fi ld litti d l t h t f th h t l tti

g [ ]g [ ]


crystal-field splitting and covalent character of the host lattice

3. UV Emitting PhosphorsVUV to VUV down converting phosphors - Nd3+ emitter


YPO4:Nd3+ LiYF4:Nd3+

0,8


sity

0,8


sity

0,4

0,6

mal

ised

int

ens

0,4

0,6

Rel

ativ

e in

tens

120 140 160 180 200 220 240 260 280 300 320 340 360 380 4000,0

0,2Nor

m

120 140 160 180 200 220 240 260 280 300 320 340 360 380 4000,0

0,2

Emission maxima at about 190 + 240 + 278 nm due tointerconfigurational [Xe]4f25d1 to [Xe]4f3(4IJ, 4GJ, 4FJ) transitions

Wavelength (nm) Wavelength [nm]


J J J

20

4. Efficiency of UV PhosphorsConversion efficiency as product of quantum efficiency and absorption

y p

Phosphor exc. band max. em. band max. QY @ 172 nm YPO4:Nd 160, 190 nm 190 nm 90%LaPO4:Pr 165, 200 nm 225 nm 70%YPO4:Pr 160, 190 nm 233 nm 70%YPO4:Bi 170 nm 241 nm 90%(C M )SO Pb 170 245 80%(Ca,Mg)SO4:Pb 170 nm 245 nm 80%LuBO3:Pr 240 nm 257 nm 50%YBO3:Pr 240 nm 261 nm 50%Y SiO :Pr 170 245 nm 270 nm 20%Y2SiO5:Pr 170, 245 nm 270 nm 20%SrSiO3:Pb 170, 235 nm 275 nm 80%LaMgAl11O19:Gd 170, 275 nm 311 nm 95%LaPO :Ce 170 270 nm 320 nm 90%LaPO4:Ce 170, 270 nm 320 nm 90%YPO4:Ce 170, 270 nm 335, 355 nm 55%LaMgAl11O19:Ce 170, 275 nm 340 nm 90%


4. Efficiency of UV Phosphorsy pPhosphor converted Xe2* excimer discharge lamp for disinfection

1,0 Germicidal Action Curve

Requires development of UV-C emitting

phosphors with a high conversion efficiency 0,6

0,8

nsity

(a.u

.)

Lamp spectrum of YAlO3:Pr

and a large integral overlap with GAC

e.g. Pr3+ or Bi3+ activated materials0,2

0,4

Em

issi

on in

te

Phosphor max [nm] GAC overlap [%]YPO4:Pr 233 78

200 250 300 350 4000,0

Wavelength [nm]1,0 Germicidal Action Curve

L S t YBO PYPO4:Pr 233 78YPO4:Bi 241 71YAlO3:Pr 245 71YBO3:Pr 263 61

0,6

0,8

inte

nsity

[a.u

.]

Lamp Spectrum YBO3:Pr

YBO3:Pr 263 61Line @ 265 100Line @ 311 0

0 0

0,2

0,4

Em

issi

on


200 250 300 350 4000,0

Wavelength [nm]

5. Thermal Quenching and VUV Stability

0 8

1,0

nsity

120000

140000 YPO4Pr025C YPO4Pr075C YPO4Pr150CYPO4P 200C

s]

g yUV-C Phosphors YPO4:Pr and YPO4:Bi

0,4

0,6

0,8

e em

issi

on in

ten

60000

80000

100000

120000 YPO4Pr200C YPO4Pr250C YPO4Pr300C YPO4Pr330C

on in

tens

ity [C

ount

s

0 50 100 150 200 250 300 3500,0

0,2 Integral Intensity at 233 nm Intensity at 271 nm

Rel

ativ

e

200 250 300 3500

20000

40000

Em

issi

o

YPO4:Pr

Temperature [°C]Wavelength [nm]

0,8

1,0

inte

nsity

200000

300000 UVC0803025C UVC0803075C UVC0803150C UVC0803200CUVC0803250C

y [a

.u.]

0,4

0,6

inte

gral

em

issi

on

100000

200000 UVC0803250C UVC0803300C UVC0803330C

Em

issi

on in

tens

ity

TQ1/2 of both phosphors is beyond 400 °C 0 50 100 150 200 250 300 3500,0

0,2

UVC22/03D UVC13/03A

Rel

ativ

e T t [°C]

90% at 325°C90% at 230°C200 220 240 260 280 300 320

0

Wavelength [nm]

YPO4:Bi


TQ1/2 of both phosphors is beyond 400 CEmission band of YPO4:Bi shifts towards 250 nm upon heating

Temperature [°C]

5. Thermal Quenching and VUV Stabilityg yUV-A Phosphor Lu3Al5O12:Tm and UV-B Phosphor Lu3Al5O12:Pr

8,0x104Emission spectra Lu3Al5O12:Tm3+

Ex= 264 nmslit size: Ex = 4 00 Em = 1 00

120000

Emission spectra of Lu3Al5O12:Pr (160 nm Excitation) LED8102025CLED8102075C

4,0x104

6,0x104

slit size: Ex 4.00, Em 1.00 200 K 250 K 300 K 350 K 400 K 450 K 500 K

sity

[cou

nts]

60000

80000

100000 LED8102150C LED8102200C LED8102250C LED8102300C LED8102330C

inte

nsity

[a.u

.]

300 350 400 450 500 5500,0

2,0x104Inte

ns

200 250 300 350 400 450 500 550 600 650 700 750 8000

20000

40000

Em

issi

on

0,8

1,0Emission integral Lu3Al5O12:Tm3+

u.]

Wavelength [nm]

0,7

0,8

0,9Colour Points of Lu3Al5O12:Pr

200 250 300 350 400 450 500 550 600 650 700 750 800

Wavelength [nm]

0,4

0,6

mal

ised

Inte

nsity

[a.u

0,3

0,4

0,5

0,6

330°C

BBL

y

25°C

Phosphors does not show significant quenching up to 250 °C250 300 350 400 450 500

0,0

0,2 Emission Integral

Ex= 264 nm

norm

Temperature [K]

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,80,0

0,1

0,2BBL

x


Phosphors does not show significant quenching up to 250 C, but strong change of spectral power distribution, resulting in a red-shift

5. Thermal Quenching and VUV Stabilityg yPr3+ doped fluoride and garnet in Xe excimer discharge lamps

110

90100110

nsity

708090

ve in

ten

405060

Rel

ativ

400 100 200 300 400

t [h]

Fluorides show severe degradation

t [h]


Garnets are impressively stable!

6. Conclusions and Future Trends6. Conclusions and Future TrendsHg low-pressure lamps

S t f UV A d UV B h h ll t bli h d• Set of UV-A and UV-B phosphors well established• Degradation due to Hg consumption and phosphor damage limits lifetime to

less than about 1000 h

Xe excimer discharge lamps

• Arbitrary UV spectra feasible • UV-A phosphor with a high VUV efficiency is LaMgAl11O19:Ce• Gd3+ activated UV-B phosphors can be sensitised by the host lattice, by Nd3+,

or by Bi3+or by Bi3• Lu3Al5O12 is an ideal host lattice for efficient UV emitting phosphors due to

the suitable band gap • YPO4:Bi and YPO4:Nd are the most efficient UV-C and VUV phosphors so far4 4• VUV phosphors compliable with Xe excimer lamps should be derived from

lattices, which are alkaline in character and have a sufficiently wide band gap, e.g. La14Si9O39 or Y9Li(SiO4)6O2

• Novel UV emitting VUV phosphors will enable attractive novel application


Novel UV emitting VUV phosphors will enable attractive novel application areas for Xe2* discharge lamps

6. Conclusions and Future Trends6. Conclusions and Future TrendsAlGaN LEDs as UV radiation sources?

Semiconductor Band gap [eV] [nm]GaN 3.5 360 AlN 6.0 210

Status early 2010 (Appl. Phys. Express 3, 031002, 2010)250 nm 1 18% EQE @ 4 8 mW250 nm 1.18% EQE @ 4.8 mW262 nm 1.54% EQE @ 10.4 mW

Development goals (Nichia)Development goals (Nichia)• 365 nm 5 W LEDs • 260 nm “mW” LEDs

Recent patent applications• UV-C LED µ-photo reactors• UV-C LED storage container


U C sto age co ta e• UV LED tanning equipment

AcknowledgementAcknowledgement

Many thanks to my co-workers and colleagues:

Dr. Helga BettentrupDavid EnselingDr. Georg GreuelRolf GerdesBenjamin HerdenArturas KatelnikovasJagoda KucDaniel MichalikDr. Julian PlewaTatjana RatProf. Cees RondaSebastian SchwungLisa SiewertHilke Sonntag


gDr. Dominik Uhlich

Thanks for your kind attention!


recent developments on uv emitting phosphors · 1. application areas of uv radiation photochemistry...

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