Development of Polymer Systems with High Electron Mobility for

Photovoltaic Applications

Development of Polymer Systems with High Electron Mobility for

Photovoltaic Applications

Jie Hu, Dong Zhang, Shi Jin, Stephen Z.D. Cheng and Frank W.

Harris

The Maurice Morton Instituteof Polymer Science

The University of AkronAkron, OH 44325-3909

To develop materials with high

electron mobility for photovoltaic

applications

ObjectiveObjective

Utilization of nitrogen-containing heterocyclic

structures

N

R

R

Ar' Ar* *

n

X

Poly(pyridinium salts) Poly(quinoxalines)

N

N

*

*

R

ApproachApproach

Specific objective of this work is to develop discotic/planar liquid crystalline compounds that display high electron mobilities.

Discotic liquid crystalline compounds have been prepared that exhibit high hole mobilities.

Adam, D.; Schumacher, P.; Simmerer, J.; Haussling, L.; Siemersmeyer, K.; Etzbach, K.H.; Ringsdorf, H.; Haarer, D. Nature 1994, 371, 141.

Discotic Liquid Cyrstalline Compounds

Discotic Liquid Cyrstalline Compounds

N

NN

N

OR

OR

RO

RO

OO

OO

BenzeneH2N

H2N

OR

OR

+

1 2

3

3a, R = n-C10H21

3b, R = n-C11H23

3c, R = n-C14H29

3d, R =

3e, R =

Preparation of Target Compounds

Preparation of Target Compounds

Br

Br

Br

Br

OMe

OMe

MeO

MeO

OH

OH

HO

HO

O

O

O

O

CCl4

Br2

CH3OH

DMF, CuI

BBr3

CH2Cl2

O2

1

Synthesis of 4,5,9,10-Tetraone Pyrene

Synthesis of 4,5,9,10-Tetraone Pyrene

O2N

O2N

OCH3

OCH3

HBrO2N

O2N

OH

OH K2CO3, DMF

RBr

H2N

H2N

OR

OR

HCOO-NH4+

Pd/C, C2H5OH, THF

O2N

O2N

OR

OR

2

Synthesis of 4,5-Diamino-1,2-bisalkoxy Benzenes

Synthesis of 4,5-Diamino-1,2-bisalkoxy Benzenes

The transition temperatures (°C) were determined by DSC at 10 °C/min, the phase types were suggested by PLM and WAXD.

Compound R Phase transition

3a n-C10H21 K LC I

3b n-C11H23 K LC I

3c n-C14H29 K I

3d 2-methylhexyl K I

3e 3,7-dimethyloctyl K I

213 268

210 234

202

> 350

316

Phase Transition Compounds of 3a-e

Phase Transition Compounds of 3a-e

100 m

The picture was taken at 261The picture was taken at 261ooC cooling from C cooling from the isotropic phasethe isotropic phase

PLM Micrograph of 3aPLM Micrograph of 3a

Cyclic Voltammetry of C10 Discotic Liquid Crystal

in Dichlorobenzene w/ TBAF4 electrolyte

mV-1200 -1000 -800 -600 -400 -200 0

Cur

rent

, A

-2

0

2

4

6

8

E1/2 = -0.868 V vs AgCl

E1/2 = -1.065 V vs NHE

Square Wave Voltammetry of C10 Discotic Liquid Crystal

in Dichlorobenzene w/ TBAF4 electrolyte

mV

-1400 -1200 -1000 -800 -600 -400 -200 0

Cur

rent

, A

-2.4

-2.2

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

E1/2 = -0.874 V vs AgClE1/2 = -1.071 V vs NHE

Current WorkCurrent Work

Structural modifications to lower transition temperatures and

increase electron affinity.