DSCTM Young Investigator Award 2017 · 2019. 2. 21. · OLED Light Emitting Layer Transparent...

MATERIALIAVANZATI

Advancedmaterialsforsolar-energyconversion,lighting,andphotocatalysis

FilippoMontiFixed-termResearcher

IstitutoperlaSintesiOrganicaelaFotoreattivitàViaPieroGobetti101,40129Bologna

DSCTM Young InvestigatorAward 2017

light-to-electricity electricity-to-light

light-to-chemistry

Solar-energyconversion,lighting…Twosidesofthesamecoin…

SOLARENERGYCONVERSIONLight-harvestingsystems

Electron-acceptormoleculesSupramolecularsystemsPhotoactivedendrimers

LIGHTINGTECHNOLOGIESIONICTRANSITION-METALCOMPLEXES

CyclometalatedIr(III)complexesCopper(I)complexes

FilippoMonti,ISOF,Bologna

light-to-chemicals

Solar-energyconversion,lightingandphotocatalysisTwobirdswithonestone…

PHOTOCATALYSISCyclometalatedIr(III)complexesforselectiveorganicreactions

Re(I)complexesforCO2 reduction


Solar-energyconversion,lightingandphotocatalysisMyresearchinterests

SOLARENERGYCONVERSIONLight-harvestingcomplexesElectron-acceptormoleculesSupramolecularsystemsPhotoactivedendrimers






Solar-energyconversionNaturalvs. artificialphotosynthesis

CHARGE-SEPARATIONUNIT

(electrontransfer)




(electrontransfer)


Solar-energyconversion— ANTENNALight-harvestingsystems

Polyhedron,2014, 82,122.SpecialIssueonMolecularMaterialsonSolar-EnergyConversion,invitedpaper

[Ru(bpy)2(PT)]2+3LCexcitedstate

withhighmolarabsorptivity[Ru(bpy)3]2+

3MLCTexcitedstate

The use of π extended ligands in Ru(II) complexes increases molar absorptivities,leading to the formation of panchromatic absorbers.

FilippoMonti

Solar-energyconversion— ANTENNALight-harvestingsystems

[Ru(bpy)3]2+3MLCTexcitedstate

[Ru(PT)3]2+3LCexcitedstate

withhighmolarabsorptivity

Polyhedron,2014, 82,122.SpecialIssueonMolecularMaterialsonSolar-EnergyConversion,invitedpaperFilippoMonti

Solar-energyconversion — DENDRIMERICANTENNAPhotoactivedendrimersforlightharvesting

ONO

N OO

NN

O

OO

OOO O O

O

O O

O

OO

O

O

OR

RO

OO

O

O

OOR

RO

O

O

OO

O

O

OR

OROO

OO O

O

RO

O

OO

OO

O

OO

O

O O

O

O

OR

OR

OO

O

O

ORO

OR

O

O

OO

O

O

RO

RO OO

OOO

O

OR

OR

O

O

R = C H16 33

NewJ.Chem.2011, 35,2234.SpecialIssueonDendriticMolecularNanostrutures,invitedpaperFilippoMonti,ISOF,Bologna

Solar-energyconversion— DENDRIMERICANTENNAPhotoactivedendrimersforlightharvesting

NewJ.Chem.2011, 35,2234.SpecialIssueonDendriticMolecularNanostrutures,invitedpaper

ONO

N OO

NN

O

OO

OOO O O

O

O O

O

OO

O

O

OR

RO

OO

O

O

OOR

RO

O

O

OO

O

O

OR

OROO

OO O

O

RO

O

OO

OO

O

OO

O

O O

O

O

OR

OR

OO

O

O

ORO

OR

O

O

OO

O

O

RO

RO OO

OOO

O

OR

OR

O

O

R = C H16 33

FINALENERGYCOLLECTOR




(electrontransfer)


Solar-energyconversion— CHARGE-SEPARATIONUNITNovelelectron-acceptormolecules

J.Phys.Chem.A2015, 119,10677;Chem.Eur.J. 2014,20,202.

We look for alternatives to standard electron-acceptors molecules (i.e., quinone, perylenediimideand fullerene derivatives).

N N

N

NNN

N N

NNN

N

NNN

N N

Bestelectronacceptor(Ered =–0.32Vvs. Fc/Fc+)

hn


Solar-energyconversion— CHARGE-SEPARATIONUNITNovelelectron-acceptormolecules

J.Phys.Chem.A2015, 119,10677.

FC

S1

S0

CI0.45 eV [0.22 eV]

1.45 eV[1.18 eV]

3.81 eV[2.92 eV]

2.49 eV[1.46 eV]

S0

S1 CI

SA2-CASSCF(12,11)/6-31G(d)[CASPT2single-pointcorrection]

N N

N

NNN

N N

NNN

N

NNN

N N


Solar-energyconversion— CHARGE-SEPARATIONUNITSupramolecularsystemsforelectrontransfer

Chem.Eur.J. 2014,20,202.

N

NN

N

R

R

R

ZnO

O

N

N

N

N

N

N

N

NN

N

R

R

R

ZnO

O

N

N

N

N

N

N

DYADSFORCHARGESEPARATION

FilippoMonti,CNR,Italy

Solar-energyconversionPhotoactivedendrimersforlightharvestingandchargeseparation

Chem.Eur.J.2014, 20,223.

C60–ZnP+

Holehopping

C60

hn

C60

LONG-LIVEDCHARGE-SEPARATEDSTATE









LightingtechnologiesHistoricaloverview:fromincandescentlampstosolid-statelighting

L

umin

ous

effic

acy

/ lm

/W

100

50

1875 Years

1975 2000 2025

150

1925

205

01900 1950 2050

1965

High pressuresodium-vapour lamp

1938Fluorescent tube

1996White LED

1999White OLED

1879Incandescent bulb 1959

Halogen lamp

Angew.Chem.Int.Ed.2012, 51,8178.FilippoMonti,ISOF,Bologna

LightingtechnologiesSolid-statelightingdevices:LEDvs. OLEDs

COBLED“surface”(anarrayofdistinctpointsources

COB=ChipsonBoard)

OLEDsurface(arealflat,thinSSL…potentiallyflexible)


LightingtechnologiesOLEDsareaconsolidatedtechnology,butstillveryexpensive…

Metal

TCOHIL

HTL Ligh

t Em

ittin

g La

yer ETL

EIL

MetalTCO

Ligh

t Em

ittin

g La

yer

Metal

TCO

Ligh

tEm

ittin

gLa

yer

ENER

GY

vacuum

ENER

GY

vacuum

Electron Injection LayerElectron Transport Layer

Light Emitting LayerHole Transport Layer

Transparent Conductive OxideHole Injection Layer

Metal

Substrate

OLED

Light Emitting LayerTransparent Conductive Oxide

Metal

Substrate

LEC

ADVANTAGES• thin, light and flexible devices• high brightness and contrasts• consolidated technology (it is on market)

DISADVANTAGES• multilayer structure• vacuum sublimation• neutral emitters only• low work-function metals• rigorous encapsulation (water is a problem)


LightingtechnologiesLECsaremuchcheaperthanOLEDs,butstilltobeimproved…

ADVANTAGES• few-layer architecture• air-stable electrodes• charged emitters• rigorous encapsulation not required

DISADVANTAGES• low stability• turn-ontime&lifetime• true-blue LECs are rare• …still a lot of work to do.

Metal

TCOHIL

HTL Ligh

t Em

ittin

g La

yer ETL

EIL

MetalTCO

Ligh

t Em

ittin

g La

yer

Metal

TCO

Ligh

tEm

ittin

gLa

yer

ENER

GY

vacuum

ENER

GY

vacuum

Electron Injection LayerElectron Transport Layer

Light Emitting LayerHole Transport Layer

Transparent Conductive OxideHole Injection Layer

Metal

Substrate

OLED

Light Emitting LayerTransparent Conductive Oxide

Metal

Substrate

LEC


N

N

IrN

N

+

LightingtechnologiesThebestactivematerialsinLECsarecyclometalatedIr(III)complexes

ADVANTAGES• high emission quantum yields• high colour tunability (from blue to red)

MAIN DISADVANTAGE• blue-emitting complexes have limitations

Angew.Chem.Int.Ed.2012, 51,8178.

LOOKINGFORSTRATEGIESTOOBTAINSTABLEANDEFFICENT

BLUE-EMITTINGCOMPLEXES


LightingtechnologiesIoniccyclometalatedIr(III)complexes:easycolourtunability

stabilize

destabilize

HOMO

LUMO

Archetypalcomplex

Emission maximumat:

595 nm

N

N

IrN

N

+

535nm

N

N

IrN

N

+

F

F

F

F

N

N

IrN

N

+N

N

491 nm

Datainoxygen-freeCH2Cl2 at298K.


LightingtechnologiesIoniccyclometalatedIr(III)complexes:easycolourtunability

HOMO

LUMO

Archetypalcomplex

Emission maximumat:

595 nm

N

N

IrN

N

+

Emission maximumat:

463nm

N

N

Ir

F

FF

F

N

N

+

N

N



LightingtechnologiesSky-blueemissionisthemostchallengingtoachieve…

ARCHETYPALCOMPLEXlem = 595nmF = 20%

N

N

Ir

+

N

N

lem = 455nmF = 45%Inorg.Chem.2012, 51,2263.

N

N

Ir

+

C

C

N

N

lem = 472nmF = <1%Inorg.Chem.2013, 52,10292.

N

N

Ir

+

N

N

N



N

N

Ir

+

N

N NN

NNN

N


N

N

Ir

+

N

N

N

N

P


LightingtechnologiesUsingphenyl-tetrazoles ascyclometalatingligandsinIr-iTMC forLECs.

Another possibility is to change the standard phenyl-pyridine cyclometalatingligands with higher-field ligands, like phenyl-tetrazoles.

N

N

Ir

+

N

N

ARCHETYPALCOMPLEXMLCTstate

lmax = 595nmPLQY= 20%Lifetime= 565nsE

mis

sion

inte

nsity

/ a

.u.

700650600550500450400Wavelength / nm

N

N

Ir

+

N

N NN

NNN

N

TetrazolecomplexMLCTstate

lmax = 532nmPLQY= 65%Lifetime= 1267ns

Inorg.Chem.2014, 53,7709.


LightingtechnologiesUsingphenyl-tetrazoles ascyclometalatingligandsinIr-iTMC forLECs.

Another possibility is to change the standard phenyl-pyridine cyclometalatingligands with higher-field ligands, like phenyl-tetrazoles.

N

N

Ir

+

N

N

Em

issi

on in

tens

ity /

a.u

.

700650600550500450400Wavelength / nm

N

N

Ir

+

N

N NN

NNN

N


Inorg.Chem.2014, 53,7709.

LightingtechnologiesAphenyl-tetrazolebasedcomplexwasoptimizedforthedevice

Due to the promising photophysical properties, the complex was tested in LECs.The devices show remarkable luminance but low stability.

Devicedrivenbyapulsedcurrentof100Am–2.

Inorg.Chem.2014, 53,7709.FilippoMonti,ISOF,Bologna

The emission colour is not the only parameter to be optimized in a LEC.Some important figures of merit used to characterize LEC performances are listedbelow:

1) the luminance and efficiency:• bulky substituents;• host-guest approach.

2) the turn-on time:• use of ionic liquids;• pulsed driving.

3) the stability:• hydrophobic substituents;• “caged” complexes…

100

50

250 Time / h

75 100 125

200

150

50 150

250

0

Lum

inan

ce /

cd

m–2

Turn-on

Stability

Efficiency / Luminance

Angew.Chem.Int.Ed.2012, 51,8178.

LightingtechnologiesSomeimportantparameterstomonitorinLECs…


LightingtechnologiesNotonlyphotophysics,butalsodevicetestingandoptimization

lem = 452nmF = 24%

P

Em

issi

on in

tens

ity /

a.u

.

700650600550500450400Wavelength / nm

with ionic liquid (1:1) in PMMA 5% w/w

in LEC @ 6V ITO / PEDOT:PSS / complex & IL (4:1) / Al

lem = 452nmF = 52%

N

N

Ir

+

C

CN

N

N

N

IrC

C

+

N

N

FaradayDiscuss.2015, 185,223.

Lightingtechnology— ThegreatestcurseTherarestmetalonEartharethebestforactivematerials!

Iridium is the rarest metal in Earth’s crust, followed by other metals used in SSL,like Pt (for OLEDs) and Ru.


Lightingtechnology— PossiblealternativesIr(III),Pt(II)andRu(II)canbesubstitutedbyCu(I)orotherd10 metals

Chem.Commun.2008, 2185

LIMITATIONS• ligandexchangeinsolution• irreversibleredoxbehaviour• largeexcited-statesdistortions

ADVANTAGES• veryabundantonEarth• emissionfromtripletstates• lackoflow-lyingMCstates


LightingtechnologyOurresearchonluminescentCu(I)complexes

N

NCu

P

P

+

R

R

Cu

P

P

+

NN N

N

NN

NCu

P

P

+

R

R

R

N

Cu+P

NCu+

3

Inorg.Chem.2013, 52,12140. Chem.Eur.J.2014, 20,12083. DaltonTrans.2013, 42,997.

Polyhedron2014, 82,158.

NH2N Cu

NH2N

NNH2

Cu

NNH2

II

8

DaltonTrans.2016, 45,17939.


LightingtechnologyOurresearchonluminescentCu(I)complexes

R

N

Cu+P

NCu+

3

Polyhedron,2014, 28,158-172.Dinuclear helical

complexes

at298K lmax[nm]

PLQY[%]

Tau[µs]

powder 492 81 19

5 V7 V8 V








PhotocatalysisIr(III)photocatalystsforradicalmetylationofMichaelacceptors

Chem.Sci.,2017, 8,1613.

NN

NN

Ir

CF3

CF3F

FF

F +

MacMillancatalyst

NN

NN

Ir

NNN

N NN

+

“Ourcatalyst”

S

SOH

O

– CO2

+ B

[Ir(III)]*

S

S

REWG

S

S

REWG

– BH+

S

S

REWG

+ BH+

S

S

REWG – B

E.T.

E.T.

[Ir(II)]

[Ir(III)]

h


PhotocatalysisIr(III)photocatalystsforolefinalkylationsbyZn-sulfinatederivatives

ACSCatal.,2017, 7,5357.

NN

NN

Ir

CF3

CF3F

FF

F +

MacMillancatalyst

P

N

NC

C

CRe

O

O

O

N

N

C

C

C

CRe

O

O

O

OHO

N

N

C

C

C

CRe

O

O

O

O

+ e–

+ e–, H+

+ CO2– CO

– H2O+ H+

N

N

C

C

C

CRe

O

O

O

OO

N

N

L

C

C

CRe

O

O

O

N

N

L

C

C

CRe

O

O

O

+ e–

– e–

– L

+ L

L = pyridine or solvent molecule

+ 0 0

0

O+

+

PhotocatalysisAnewstimulatingadventure — CO2 photoreduction

CO2 PHOTOREDUCTIONbyRe(I)complexes

ProgettobilateraleCNR–CONICET,2015-2016FilippoMonti,ISOF,Bologna

N N N

n 200

Re(CO)3(N^N)+

N

N

N

C

C

CRe

O

O

O

CF3SO3

N

N

N

C

C

CRe

O

O

O

N

N

N

C

C

CRe

O

O

O

N

N

CF3SO3CF3SO3

Polymeric complexgeneral formula

PhotocatalysisAnewstimulatingadventure — CO2 photoreduction

ProgettobilateraleCNR–CONICET,2015-2016FilippoMonti,ISOF,Bologna

This work was supported by the Italian Ministry of Research (PRIN-INFOCHEM andFIRB-SUPRACARBON projects) and by the National Research Council of Italy(progetto bandiera N-CHEM and bilaterale CNR-CONICET).I would like to thank also the CELLO project (FP7) for the opportunity it gave me tostart my research activity and to work with a great network of scientists.

AcknowledgmentsInstitutionsandprojects

light-to-electricity electricity-to-light

light-to-chemistrylight-to-chemicals


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DSCTM Young Investigator Award 2017 · 2019. 2. 21. · OLED Light Emitting Layer Transparent...

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