Application: OFETs

Gate Insulator

Gate

Semi-Condutor

Source and Drain

Bottom Gate

Gate Insulator

Gate

Semi-Condutor

Source and Drain Top Gate

-8,0E-07

-7,0E-07

-6,0E-07

-5,0E-07

-4,0E-07

-3,0E-07

-2,0E-07

-1,0E-07

0,0E+00

-60-50-40-30-20-100Uds [V]

Ids

[A]

Ugs = 10V

Ugs = 0V

Ugs =-10V

Ugs = -20V

Ugs = -30V

Ugs = -40V

Ugs = -50V

Ugs = -60V

1,0E-10

1,0 E-09

1,0 E-08

1,0 E-07

1,0 E-06

-60 -40 -20 0 20 40 60Ugs [V]

|Ids|

[A

]

Uds = -1V

Uds = -10V

OutputTransfer

APE (All Printed Electronics)

RT 150 °C100

150

200

250

300

350

400

450

On

/Off

Rat

io

PTPA1 THF PTPA1 CHCl

3

PTPA2 THF PTPA3 THF

RT 150 °C

4,0x10-6

6,0x10-6

8,0x10-6

1,0x10-5

1,2x10-5

1,4x10-5

1,6x10-5

1,8x10-5

2,0x10-5

2,2x10-5

Ch

arg

e C

arri

er M

ob

ility

[cm2 /V

s]

PTPA1 THF PTPA1 CHCl

3

PTPA2 THF PTPA3 THF

Optical Properties

Polytriarylamine-type hole conductorsBenjamin Souharce1, Julien Lannelongue1, Michael Forster1, Achmad Zen2, Dieter Neher2,

Ulrich Hahn 3, Arved C. Hübler3, Ullrich Scherf1

IntroductionResearch into organic field-effect transistors (OFETs) has been rapidly growing in the past few years. The use of organic materials to build semiconductor devices promises low-cost electronics fabricated by printing techniques on large areas and flexible substrates[1]. Due to their amorphous behavior, highly stable polytriarylamine based hole transporting materials are well-skinned for designing OFETs both in top and bottom gate configuration [2].In the current work, we synthesized different types of polytriphenylamines in order to increase the processibility of the material for printed OFETs. The structure was varied in the side-chain and in the backbone. The dibromotriphenyamine monomers have been synthesized by Buchwald-Hartwig coupling reaction of arylanilineand 1-bromo-4-iodobenzene, and then polymerized by the nickel(0) mediated aryl-aryl coupling according to Yamamoto. Herein, we describe the synthesis and the optical properties of the resulting polymers. and their application in OFETs devices.

1 Bergische Universität Wuppertal, Makromolekulare Chemie, Gaußstr.20, D-42097 Wuppertal2 Universität Potsdam, Institut für Physik, Am Neuen Palais 10, D-14471 Potsdam

3 Institut für Print- und Medientechnik, Technische Universität Chemnitz, Reichenhainer Str. 70, D-09126 Chemnitz

souharce@uni-wuppertal.de

Synthesis

PTPA1 PTPA2 PTPA3 PTPABu PTPAPh

I

BrNH2

R

N

R

Br

+ 2 N

n

R

N

n

N

n

N

n

Bu

N

n

N

n

Br

Pd2(dba)3

Buchwald-Hartwig

Nickel (0)

Yamamoto

NH2

N+ 2

I

Br Br Br

N N

n

Nickel (0)

Yamamoto

Pd2(dba)3

Buchwald-Hartwig

P4TPA3

PTPA1 PTPA2

I

BrNH2

R

N

R

Br

+ 2 N

n

R

N

n

N

n

N

n

Bu

N

n

N

n

Br

Pd2(dba)3

Buchwald-Hartwig

Nickel (0)

Yamamoto

11200490087003760050002700Mn

(g.mol-1)

191003450021400687002620063400Mw

(g.mol-1)

P4TPA3PTPAPhPTPABuPTPA3PTPA2PTPA1Polymer

Film

Solution

426428448422436Emission

(nm)

369377390376369Absorption

(nm)

428424439419435Emission

(nm)

370375386374377Absorption

(nm)

PTPAPhPTPABuPTPA3PTPA2PTPA1Polymer

Film

Solution

430448Emission

(nm)

384390Absorption

(nm)

456439Emission

(nm)

383386Absorption

(nm)

P4TPA3PTPA3Polymer

493On/Off Ratio

4,86.10-4µ [cm2/Vs]

OFET Parameters[3]

UV-Vis & Photoluminescence

300 400 500 600

Em

issi

on [a

.u.]

Abs

orp

tion

[a.u

.]

Wavelength [nm]

PTPA3 UV PTPA3 Fluo P4TPA3 UV P4TPA3 Fluo

300 400 500 600

Em

issi

on [a

.u.]

Ab

sorp

tion

[a.u

.]

Wavelength [nm]

PTPA1 UV PTPA1 Fluo PTPA2 UV PTPA2 Fluo PTPA3 UV PTPA3 Fluo PTPABu UV PTPABu Fluo PTPAPh UV PTPAPh Fluo

300 350 400 450 500 550 600

Em

issi

on [

a.u.

]

Ab

sorb

ance

[a.u

.]

Wavelength [nm]

PTPA1 Film UV PTPA1 Film Fluo PTPA2 Film PTPA1 Film Fluo PTPA3 Film PTPA3 Film Fluo PTPABu Film PTPABu Film Fluo PTPAPh Film PTPAPh Film Fluo

300 400 500 600

Em

issi

on

[a.u

.]

Abs

orp

tion

[a.u

.]

Wavelength [nm]

PTPA3 Film UV PTPA3 Film Fluo P4TPA3 Film UV P4TPA3 Film Fluo

939,9On/Off Ratio

-7Ut [V]

1,13.10-3µ [cm2/Vs]

OFET Parameters

[1] J. Veres, S.D. Ogier, G. Lloyd, Chem. Mater, 2004, 16, 4543[2] J. Veres, S.D. Ogier, S.W. Leeming, D.C. Cupertino, S.M. Khaffaf, Adv. Funct. Mater., 2003, 13(3), 199[3] J.A.V. Allen, B.A. Brown, S.W. Leeming, J.D. Morgan, J. Veres, WO Patent 00/78843 A1,2000.

Results and Discussions

�PTPA polymers can be synthesized through a simple two step reaction. They are amorphous materials.�PTPA polymers show significant transistor behaviour. The charge carrier mobilities can be increased by annealing and changing the solvent during processing.�Comparing to P3HT, the charge carrier mobilitiesµ of the PTPA polymers are one order of magnitude lower. The charge carrier mobilities can beincrased in OFETs with top-gate structure.�The UV-Vis spectra show a slight bathochromic shift with the increasing number of methyl groups of the side-chains. �First APE (all printed electronics) OFETs demonstratethat the PTPA polymers are promising candidates for printed transistors.�The below shown structures are in progress.

NN

n

N

Br Br

Sn

Sn

+ 2Pd[P(Ph3)]4

Stille

PClCl

I

Br

P

Br Br

+

Br

P

n

nBuLi, THF

PCl3, THF

Nickel (0)

Yamamoto

nBuLi, Ether