F&A SS 2017 Einleitung Handout - meerholz.uni-koeln.de · Molekül Formulierung Charakterisierung Material Werkstoff Bauteil Struktur/Eigenschafts‐ Beziehungen Funktionsprüfung

1

Chemistry DepartmentCologne University

Funktion & Anwendung

Klaus Meerholz

Modul F&A, SS 2017

2 Klaus Meerholz

DepartmentCologneUniversity

Chemistry

Optisch

• Flüssigkristall‐Display (LCD)

Elektrochemisch & optisch

• Elektrochromie

Elektrisch & optisch

• (Hybrid‐) Solarzelle

• (Organische Leuchtdiode)

Anwendung

• Weitere „wichtige“ Parameter

• Transfer, Entrepreneurship

Funktion & Anwendung Versuche

3 Klaus Meerholz


Chemistry

Molekül

Formulierung

CharakterisierungMaterialWerkstoffBauteil

Struktur/Eigenschafts‐Beziehungen

Funktionsprüfung

Funktion und Anwendung

AnwendungFunktion

Synthese

4 Klaus Meerholz


Chemistry

Physik

Material‐wissenschaft

Lebens‐wissenschaften

eine Probe, viele Meßmethoden

Auswahl von Verbindungen & Meßverfahren, Derivatisierung

Chemie

Interdisziplinarität

Syntheserouten

viele Verbindungen Tabelle

High‐ThroughputScreening

5 Klaus Meerholz


Chemistry

• Wissenschaft mit Anwendungsbezug,

• nicht Eigenschaften einzelner Moleküle sind relevant,

sondern die eines Ensemble von vielen Molekülen

mit vielfältigen inter‐molekularen Wechselwirkungen

• Volumenmaterial (bulk), Werkstoff, Material, Wirkstoff, …

• Komposite (Mischungen)

Angewandte Forschung

6 Klaus Meerholz


Chemistry

Eigenschaftsprofil

elektrische Isolator, Halbleiter, Leiter

optische Aussehen / Ästetik, Homogenität, Brechungsindex, Transparenz, Emission, Grenzflächen

thermische meistens unveränderte Eigenschaften bei Temperaturwechsel erwünschtgewollte Änderungen Thermooptische Schalter, Effektlacke

mechanische Steifigkeit Flexibilität, Reißfestigkeit, HaftungOberflächenqualität (glatt / rauh)

wirtschaftliche Preis (Möglichkeiten zur Massenfertigung), Sicherheit, Lebensdauer, Umweltverträglichkeit, Reproduzierbarkeit, Zuverlässigkeit, Packaging

Alle Parameter müssen gleichzeitig zufriedenstellend erfüllt sein!!

2

7 Klaus Meerholz


Chemistry

• Invention: (grundlegende) Erfindung Universitäten

• Innovation: erfolgreiche Markteinführung Industrie

Invention / Innovation

8 Klaus Meerholz


Chemistry

Chemistry DepartmentCologne University

Organische Elektronik

Klaus Meerholz

Modul F&A, SS 2017

10 Klaus Meerholz


Chemistry

AK Meerholz

Organische Leuchtdioden, Photovoltaik, Feldeffekttransistoren,

Biosensoren, Photorefraktive Materialien (Holographie),…

11 Klaus Meerholz


Chemistry

Inorganic Semiconductors

70 years ago: transistor, IC

60 years ago: transistor radio

50 years ago: TV, VCR

40 years ago: personal computer

30 years ago: internet, e-mail

20 years ago: cellular phones, GaN

10 years ago: GPS, bluetooth, RFID

12 Klaus Meerholz


Chemistry

Organic Semiconductors

35 years ago: conductive polymers

25 years ago: organic light-emitting diodes (OLED)

20 years ago: organic photovoltaics (OPV)

15 years ago: organic lasers (OLAS)

10 years ago: organic field-effecttransistors (OFET)

5 years ago: organic memories(OMEM)

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13 Klaus Meerholz


Chemistry

• Organic Electronics (OE): active components contain„organic“ elements C, H, N, O, S, … (no Si, Ge, …)

• Established research area since 1980s• Nobel price 2000 (Heeger, McDiarmid, Shirakawa)

• Large economic potential Several 100 billions $/€ in 2020

• Hot topic worldwide, in particular in Asia Light‐emitting diodes (OLED) Photovoltaics (OPV) Electronic circuitry (OFET)

• Focus area of European Commission(Horizon 2020)

• Technological advance mainly throughtrial and error

• Fundamental understanding often missing

Background

14 Klaus Meerholz


Chemistry

Forschungsfokus: Funktionale Kunststoffe

Elektrische Aspekteorganische (Halb-) Leiterantistatische Beschichtungen Xerographie, Photokopierer

Thermische AspekteNicht erweichend

Mechanische AspekteFlexibel aber formstabilFliessverhalten

AnwendungenOrganische Leuchtdioden (OLED)Organische Solarzellen (OPV)Organische Transistoren (OFET)Organische Speicher (OMEM)Holographische Datenverarbeitung

Optische Aspekte

flüssigkristalline PolymereLackePolarisatorfolien

lichtstrukturierbare Polymere PhotoresistsSicherheitsmerkmaleoptische Speicher

CD-ROM, CD, DVDHolographischer Massenspeicher

Wellenleitung on-chip Datenübertragung, optische Sensoren

elektrooptische Schalter (NLO) ultraschnelles Schalten Telekommunikation

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Chemistry

Organic Electronics?

• materials monomers (small molecules), oligomers, polymers

• properties semiconducting, emissive, flexible…

• processing from solution (printing) or vacuum (PVD)

• applications LEDs, PV, FET, Sensors, …

Organic Electronics

electronic circuits based on functionalised organic materials „plastic electronics“

16 Klaus Meerholz


Chemistry

low production costs

fast production

light‐weight & paperthin

flexible

transparent

low power consumption

self‐emissive

wider viewing angles

higher contrast ratio

Sony 2007

Sony 2007

Advantages

potential fornew electronic revolution

Burda Druck

MAN Roland

COMEDD 2012

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Chemistry

General device stack: OLED & OPV

„bottom“‐contact (ITO, metall grids)

„top“‐contact (Ca/Ag, Ba/Ag, Al, ….)

active layer (mono‐, oligo‐, polymer, mixed systems, …)

hole‐injection or hole‐collection (Pedot, MoO3, …)

substrate (glass, PET, …)

• active layer: ca. 100 nm

• complete device: (w/o substrate) ca. 400‐500 nm thickness of the device is mainly determined by the substrate

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Chemistry

• Injektion

• Transport

• Rekombination

OLED

Anode

Kathode

Emitter

Ca. 100 nm

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Chemistry

Organische Leuchtdioden

source: LG Electronics

source: BMW

source: news.oled‐display.net

source: osram‐oled.com

source: samsung.de

source: Siemens/Osram

source: microoled.com

20 Klaus Meerholz


Chemistry

Sony 2007

Applications

OLEDs ‐‐ Organic Light‐Emitting Diodes

• displays for TV, cameras, mobile phones…

LG 2012 ???

Kodak 2003

Samsung 2011

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Chemistry

From Displays …

Picture courtesy of LG Display

55 inch diagonale

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Chemistry

The Largest OLED Display

4.5 m diagonal

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Chemistry

Applications

OLEDs _ Organic Light‐Emitting Diodes


• microdisplays for head mounted displays

and microprojectors

MicroOLED

lightblueoptics

24 Klaus Meerholz


Chemistry

Applications

OLEDs _ Organic Light‐Emitting Diodes


• microdisplays for head mounted displays and microprojectors

• signage

• lighting

CARO 2007Verbatim

Philipps Lumiblade

5

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Chemistry

…to Illumination

Pictures courtesy of Osram, Philips

Lumiblade

26 Klaus Meerholz


Chemistry

Applications

OLEDs ‐‐ Organic Light‐Emitting Diodes


• microdisplays for head mounted displays and microprojectors

• signage

• lighting

State‐of‐the‐art

• small displays in mobile phones, car radios, mp3‐player, …

• TV 15“, 1000€

Dec. 2012?? 55“, ca. 8000€

• microdisplays in HMD

• flexible displays: only prototypes

• lighting: only in designer unique pieces

(expensive)UDC 2012

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Chemistry

hole collecting contact (HCC)

substrate

electron collecting contact (ECC)


substrate


acceptor

donor

Organic Solarzellen

1. Exzitonerzeugung & Transport

2. Exzitondissoziierung

3. Freie Ladungsträger, Transport

4. Ladungsextraktion

h

hole colle

cting

contact

electron colle

cting

contact

1.

2.

3.

4.

4.

energy

-

+

+-

3.

donor acceptor

-

+-+

- +

h

+

-

bulk heterojunction (BHJ)planar heterojunction (PHJ)

active layer

Ca. 100 nm

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Chemistry

Organische Solarzellen

source: sargosis.com

source: imec.be & vtt.fi

source: holstcentre.com

source: plusplasticelectronics.com source: G24i

29 Klaus Meerholz


Chemistry

Applications

OSC _ Organic Solar Cells

• energy production: exploitation of unused surfacesPhotos: Konarka, Heliatek, BMBF

30 Klaus Meerholz


Chemistry

OSC _ Organic Solar Cells

• energy production: exploitation of unused surfaces

• energy source for mobile phones, cameras, mp3‐player, …

Applications

sunbag, Neuber

solar jacket, Scottevest

printed OSC, Konarka

State‐of‐the‐art

• efficiency in laboratories: 10.7% (Heliatek, Dresden)

• module efficiencies: ca. 3%

• first niche products

• demonstration of prototypes for flexible and transparent apps

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31 Klaus Meerholz


Chemistry

Organic semiconductors

1906 dark and photoconductivity of anthracene

1960s electroluminescence of anthracene (50‐2000 V)

1977 doping is possible in organic semiconductors

(Nobel prize for Chemistry in 2000)

1980s first efficient organic solar cell

1987 OLED via evaporation of small molcules

1990 OLED via spin‐coating of polymer layers

2007 11 inch OLED display XEL‐1 by SONY

…

A brief history…

32 Klaus Meerholz


Chemistry

aus: M. Rehahn,

ChiuZ, 37, 2003, 18.

33 Klaus Meerholz


Chemistry

Ende 1

34 Klaus Meerholz


Chemistry

General device stack: OLED & OPV

„bottom“‐contact (ITO, metall grids)

„top“‐contact (Ca/Ag, Ba/Ag, Al, ….)

active layer (mono‐, oligo‐, polymer, mixed systems, …)

hole‐injection or hole‐collection (Pedot, MoO3, …)

substrate (glass, PET, …)

• active layer: ca. 100 nm

• complete device: (w/o substrate) ca. 400‐500 nm thickness of the device is mainly determined by the substrate

35 Klaus Meerholz


Chemistry

• Injektion

• Transport

• Rekombination

OLED

Anode

Kathode

Emitter

Ca. 100 nm

36 Klaus Meerholz


Chemistry


substrate



substrate


acceptor

donor

Organic Solarzellen

1. Exzitonerzeugung & Transport

2. Exzitondissoziierung

3. Freie Ladungsträger, Transport

4. Ladungsextraktion

h

hole colle

cting

contact

electron colle

cting

contact

1.

2.

3.

4.

4.

energy

-

+

+-

3.

donor acceptor

-

+-+

- +

h

+

-

bulk heterojunction (BHJ)planar heterojunction (PHJ)

active layer

Ca. 100 nm

7

37 Klaus Meerholz


Chemistry

Organic semiconductors

1906 dark and photoconductivity of anthracene

1960s electroluminescence of anthracene (50‐2000 V)

1977 doping is possible in organic semiconductors

(Nobel prize for Chemistry in 2000)

1980s first efficient organic solar cell

1987 OLED via evaporation of small molcules

1990 OLED via spin‐coating of polymer layers

2007 11 inch OLED display XEL‐1 by SONY

…

A brief history…

38 Klaus Meerholz


Chemistry

aus: M. Rehahn,

ChiuZ, 37, 2003, 18.

39 Klaus Meerholz


Chemistry

• two major classes of organic semiconductors

– polymers, deposited via spin‐coating

– low‐molecular weight materials, deposited via evaporation

From: Organic Semiconductors, W. Brütting, in: Encyclopedia of Physics, (2005)

Organic Semiconductors, ‐electron systems

40 Klaus Meerholz


Chemistry

‐electron systems




• both with a conjugated ‐electron system:

formed by pz‐orbitals of sp2‐hybridized C atoms

From: Paula Yurkanis Bruice, „Organic Chemistry“, Pearson

sp2 hybridization

41 Klaus Meerholz


Chemistry

‐electron systems






From: Paula Yurkanis Bruice, „Organic Chemistry“, Pearson

sp2 hybridization

42 Klaus Meerholz


Chemistry

From: Grundlagen der organischen Halbleiter, W. Brütting, W. Rieß, Physik Journal 7(5) (2008)

‐electron systems






simplest example: ethene = C2H4

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43 Klaus Meerholz


Chemistry

Extended ‐systemexample: benzene = C6H6

‐electron systems

Benzenemolecular formula

BenzeneKekulé constitutional formula

Benzeneplanar hexagon

Benzenesp 2 form ‐bondings

Benzene6 p‐orbitals

Benzenedelocalized ‐orbitals

Benzenesimplified illustration

LUMO

HOMO

44 Klaus Meerholz


Chemistry

…. depend on the electronic structure of

• (single) molecules • molecular geometry

• molecular aggregation• 3D packing

Most important:Delocalizable electrons

-electronsmolecular orbitals

Optical & Electrical Properties ….

45 Klaus Meerholz


Chemistry

‐electron systems

Polymer conformation

From: Collini and Scholes Science, 323, (2009) 369.

46 Klaus Meerholz


Chemistry

‐electron systems

Polymer conformation

From: Dyakonov, Seminar Experimental Physics 2011

polymer segment with different conjugation length different energy states dep. on conjugation length & on the surrounding

47 Klaus Meerholz


Chemistry

Optical Properties

48 Klaus Meerholz


Chemistry

occupied orbitals

unoccupied orbitals

LUMO

lowest unoccupied molecular orbital

HOMOhighest occupied molecular orbital

}

}refractive index

linear regimePOLARIZATION

Optical Properties (real part)

LCD Anzeige

9

49 Klaus Meerholz


Chemistry

occupied orbitals

unoccupied orbitals

LUMO



}

}

(linear)

absorption

Optical Properties (imaginary part)

Solarzelle

50 Klaus Meerholz


Chemistry

occupied orbitals

unoccupied orbitals

LUMO



}

}luminescence

Emission

51 Klaus Meerholz


Chemistry

‐electron systems

E

E0

LUMO

HOMO

200nm290nm

380nm525nm

Extended ‐system

52 Klaus Meerholz


Chemistry

aus:

Hesse, Meier, Zeeh, Spektroskopische Methoden in der organischen Chemie, Thieme Verlag 1991

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Chemistry

well‐defined spin states: excitons tightly bound and localized on one molecule

Optical properties

Jablonski diagram

54 Klaus Meerholz


Chemistry

Potential curve and resulting spectra

r

pot. E

S0

T1

S1

ISC

h

I

E

Ph

FL abs

Optical properties

ground state

excited states

vibrational levels

10

55 Klaus Meerholz


Chemistry

aus: M. Pope, C. E. Swenberg, Electronic Processes in Organic Crystals and Polymers Oxford University Press, New York 1999.

56 Klaus Meerholz


Chemistry

Optische Spektren konjugierter Moleküle

57 Klaus Meerholz


Chemistry

‐electron systems

Color variation

400 500 700 700

[nm]

400 500 700 700

emission wavelength

N

OBe

N

OBeBq2

Eu

S

O

CF3

O

3S

N

O NO

O

NC CN

N

O

OZn

N

O

O

n nN

O

O

n

HN

NN

NH

Perylen

Coumarin 6

Zn(oxz)n

Polyfluoren

Rubren

TPP

MEH-PPVDCM

Eu(TTA)3phen

PPV

polymere emitter

58 Klaus Meerholz


Chemistry

Charge Transport

59 Klaus Meerholz


Chemistry

occupied orbitals

unoccupied orbitals

LUMO



}

} oxidationp-doping

hole generation

reductionn-doping

electron generation

Redox Activity / Doping

Elektrochromie

60 Klaus Meerholz


Chemistry

Charge transport in OS

„p‐type“ _ hole transport

occupied orbitals

unoccupied orbitalsLUMO



}

}anode cathode

11

61 Klaus Meerholz


Chemistry

Photoconductors (p‐type)


„electron rich system“

From Rubipy Scientific inc.

62 Klaus Meerholz


Chemistry


„n‐type“ _ electron transport

occupied orbitals

unoccupied orbitalsLUMO



}

}anode cathode

63 Klaus Meerholz


Chemistry

Photoconductors (n‐type)


„electron poor system“

From Rubipy Scientific inc.

64 Klaus Meerholz


Chemistry


„Hopping“ transport in amorphous solids

field [V/m]

e-

h+

e-

M M M M MMhole transport

electron transport M M M M MM

charge carriers are radical ions

problem: they react with oxygen, water and other impurities

65 Klaus Meerholz


Chemistry


DOS of energetic states

E

EF

EF

ano

de

org

anic

cath

od

e

E

ano

de

cath

od

e

LUMO

HOMO

e

h

org

anic

hEL

2

1a

1b

3

E

DOS

„Hopping transport“

66 Klaus Meerholz


Chemistry


DOS of energetic states

From: ChemPhysChem, 9, (2008), 666

Bässler model _ hopping transport in amorphous solids

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67 Klaus Meerholz


Chemistry

OLED bzw. OPV

OLED

• Injektion von Ladungsträgern

• Transport

• Rekombination

• Exzitonenbildung

• Emission

OLED

LEC

OPV

• Extraktion von Ladungsträgern

• Transport

• Dissoziation

• Exzitonenbildung

• Absorption

Bulk heterojunction

Grätzel Zelle

Documents

F&A SS 2017 Einleitung Handout - meerholz.uni-koeln.de · Molekül Formulierung Charakterisierung Material Werkstoff Bauteil Struktur/Eigenschafts‐ Beziehungen Funktionsprüfung