˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1...

6
Polymer(Korea), Vol. 29, No. 4, pp 363-368, 2005 363 1.# g«# Z 6Úæê ^ã® è ZZÒ îê /2& Û î® 6ÚæV Vê W, W ¾. îê ² kZ ", Zû® e OLED® kKn÷ G® § ÿÚÒ&r $ FÂV ßn6 Þ:. 1 Þ 3,4-ethylene dioxy- thiophene(EDOT) ê V²WÎ thiophene v²r thiophene > ® 3, 4Þ Z®V ethylenedioxy² ®®n Þ ZæKBþR& ®Ê VW² 2 V6 Þ:. Òr 6Úæ ·n 2V WÎv WC(760»780 nm)& Ê® ¢& V2gv WC &r Û² Vê ûfÊ ÞÆ, ʲ ÎÊ Û ê ®ê CRT e FPD G® júb^Êÿ "² §ÿÊ Vû®:. B ² PEDOTê p-doping n , è ZZ(550 S/cm) ¾. ®& : k®6, ÚªV ÿÊ®:ê ûfÊ Þ:. 1-3 PEDOTê r2r e Ö® Û®, g¿ ë e ÆÊ& Ò BB V k2² Ên ÞêÆ, N g Vû $Ê FÊê ÙÊ polystyrenesulfonte(PSS) ² §n Þê PEDOT-PSS(Baytron P, Bayer) Ê:. 4 PEDOT æê 6Úæ Z® k² Î{² ÎÊ Þÿ (insoluble), Þ(infusible)® V6 Þî, PEDOT-PSSê nÿÎ PSSÒ Ö² Êÿ®B PEDOTV & Ún Þ Lurq+LLL,0I0wroxhqhvxoirqdwhô#á+#Sro|+6/70hwk|ohqhglr{|wklrskhqh,Ì## Õ1a#«s#U¬Ì#0Þ# `Xó }'L}\}o}g\h# @(c# 5<(c# Ìì5c<# +5338T#5# 57¼# Q:/#5338T#8# 56¼# T,# # Vroyhqw#Hiihfwv#rq#wkh#Fkdujh#Wudqvsruw#Ehkdylru#lq## Sro|+6/70hwk|ohqhglr{|wklrskhqh,#V|qwkhvl}hg#zlwk#Lurq+LLL,0I0wroxhqhvxoirqdwh# Fkdqj#Pr#Sdun /#Wdh#\rxqj#Nlp/#Zrq#Mxqj#Nlp/#\xq#Vdqj#Nlp/#dqg#Nzdqj#V1#Vxk# Department of Materials Science and Engineering, Korea University, Seoul 136-701, Korea (Received February 24, 2005;accepted May 23, 2005) 5¨Ü Iron(III)- p-toluenesulfonateÒ r2r² ² 3,4-ethylenedioxythiophene(EDOT) ® g¿Rk2 BB V vÿ:Ò þ VÞ ¢ poly(3,4-ethylenedioxythiophene)(PEDOT) ® Z®Ê/Ê â ®ê& VÊ F®V:. þV² v ÿ:® Û®ê MeOH, EtOH G® ¢²® Acetone, MEK G® Vú®VÆ, ® ZZ wk2 280 K&r Zê MeOHÒ þV² 2"V 19.5 S/cm² Vû è®Æ, MEKÒ þV² 2"ê 2.2Ý10 -9 S/cm² W :Î Z Ò î:. vÿ: þV& Î ZZ® ªÒ zÛ® ZÊ X-ray diffraction(XRD)Ò ² PEDOT® ÂÆW ªÒ V®VÆ, ¢²®Ò þVÞ kªV óV®ê nÊ, Vú®® vÿ:Ò þVÞ &ê kk ÂÆÒ Vê Ù V®V:. B² X-ray photoelectron spectroscopy(XPS)Ò Êÿ®B S(2p) ÂÒ Ús² R Vú®Ò þV² 2"® :Î 2"& Ê §^þÊ : ¢ V®V:. Êê vÿ: PEDOT® VÊ~Î p-toluenesulfonate® çÿ² β Ù² g¿2 vÿ:® þV& Ò PEDOT® §þ~ e ÂÆV ª®6 RW² ZZV ª®ê Ù «Î®V:.G Abstract: The effects of organic solvent on the charge transport behavior of poly(3,4-ethylenedioxythiophene)/p-toluene- sulfonate(PEDOT-OTs) are investigated. The use of different organic solvents during the oxidative chemical polymerizati on of 3,4-ethylenedioxythiophene(EDOT) with Iron(III)-tosylate can greatly vary the DC conductivity of PEDOT-OTs along with molecular structure and doping concentration. For example, PEDOT-OTs prepared from methanol shows the con- ductivity of 19.5 S/cm, which is an increase by a factor of 10 8 compared to PEDOT-OTs prepared from acetone. From the X-ray diffraction (XRD) experiments, it was found that PEDOT-OTs with ketone is amorphous state, while PEDOT-OTs with alcoholic solvent shows the better defined crystalline structure in which the charge transport along and between the PEDOT chains are promoted. Chemical analysis employing X-ray photoelectron spectroscopy (XPS) revealed that t he doping concentration of PEDOT-OTs with alcoholic solvent is much higher than that of PEDOT-OTs with ketones. It is proposed that the interactions between the organic solvent and doping anion can cause the variation in doping concentration and, therefore, result in the PEDOT-OTs of different conductivities and chain structures. Keywords: charge transport, DC conductivity, poly(3,4-ethylenedioxythiophene) (PEDOT), iron(III)-p-toluenesulfonate (Fe(OTs)3), X-ray photoelectron spectroscopy (XPS). To whom correspondence should be addressed. E-mail: [email protected]

Transcript of ˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1...

Page 1: ˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1 iron(III)-p-toluenesulfonate EDOT direct oxidative chemi-

Demo

Polymer(Korea), Vol. 29, No. 4, pp 363-368, 2005

363�

1.����

��� ���� ��� �� ������ ���� ��� �

�� ���� ��� ���, ��� ��� �� ���� ��

� ��� ����, ������ � OLED� ����� �� �

����� �� ��� ���� ��.1 �� 3,4-ethylene dioxy-

thiophene(EDOT)� ���� thiophene� ���� thiophene ���

� 3, 4� �� ethylenedioxy�� ���� �� �������

�� ����� �� ���� ��� ��. ��� ��� ���

�� ��� ��(760�780 nm)� ���� ��� ���� ��

�� ��� ��� ��� ��� ���, �� �� ����

��� CRT � FPD �� ������ ��� ��� ����. �

� PEDOT� p-doping �� � , �� �����(550 S/cm)�

�� ��� � ����, ���� ����� ��� ��.1-3

PEDOT� ��� � ���� ��, �� �� � �� ��

�� �� ��� �� � ���, � � �� �� ��� ��

polystyrenesulfonte(PSS)� ��� �� PEDOT-PSS(Baytron P, Bayer)

��.4 PEDOT ��� ��� ���� �� ���� �� ��

(insoluble), ��(infusible)� ��� ��� ���, PEDOT-PSS�

���� PSS� ���� ���� PEDOT� �� ��� �

������������������ ��������������������������������������������

���������������������

���������������������

������������������

����������������������������������

�������� ������������������� ���������!������������

���������������������������������������"���#���������������������� ������

�������������� �����������������������������������������������������������

Department of Materials Science and Engineering, Korea University, Seoul 136-701, Korea

(Received February 24, 2005;accepted May 23, 2005)�

��� Iron(III)-p-toluenesulfonate� ���� � 3,4-ethylenedioxythiophene(EDOT)� ����� �� �� ���� �

��� � poly(3,4-ethylenedioxythiophene)(PEDOT)� ������� ��� ����� �� �����. ���

���� ��� MeOH, EtOH �� ���� Acetone, MEK �� ������, �� ����� ��� 280 K��

���� MeOH� ��� ��� 19.5 S/cm� �� ����, MEK� ��� ��� 2.2�10-9 S/cm� � �� ��

�� ����. ��� ��� �� ������ ��� ��� � X-ray diffraction(XRD)� �� PEDOT�

�� ��� ������, ���� ���� � ���� ���� ��, ���� ���� ���� �

�� ��� �� ��� �� �����. �� X-ray photoelectron spectroscopy(XPS)� ���� S(2p) ���

��� � ���� ��� ��� � �� ��� �� ���� � ��� �����. �� ����

PEDOT� ��� � p-toluenesulfonate�� ������ �� ��� ��� ���� ��� �� PEDOT� �

�� � �� ���� ���� ������ ���� �� �����.�

Abstract:�The effects of organic solvent on the charge transport behavior of poly(3,4-ethylenedioxythiophene)/p-toluene-sulfonate(PEDOT-OTs) are investigated. The use of different organic solvents during the oxidative chemical polymerization of 3,4-ethylenedioxythiophene(EDOT) with Iron(III)-tosylate can greatly vary the DC conductivity of PEDOT-OTs along with molecular structure and doping concentration. For example, PEDOT-OTs prepared from methanol shows the con-ductivity of 19.5 S/cm, which is an increase by a factor of 108 compared to PEDOT-OTs prepared from acetone. From the X-ray diffraction (XRD) experiments, it was found that PEDOT-OTs with ketone is amorphous state, while PEDOT-OTs with alcoholic solvent shows the better defined crystalline structure in which the charge transport along and between the PEDOT chains are promoted. Chemical analysis employing X-ray photoelectron spectroscopy (XPS) revealed that the doping concentration of PEDOT-OTs with alcoholic solvent is much higher than that of PEDOT-OTs with ketones. It is proposed that the interactions between the organic solvent and doping anion can cause the variation in doping concentration and, therefore, result in the PEDOT-OTs of different conductivities and chain structures.

Keywords: charge transport, DC conductivity, poly(3,4-ethylenedioxythiophene) (PEDOT), iron(III)-p-toluenesulfonate (Fe(OTs)3), X-ray photoelectron spectroscopy (XPS).

†To whom correspondence should be addressed. E-mail: [email protected]

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364� �������������������

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� ��� �� � �� ���� ��� ��� �� ��� �

�� ����, ������ � OLED� ����� �� �� �

���� ���� ��. ��� PEDOT-PSS� ������ �

10 S/cm� ���� �� �� ������ ��� �����

� ��� ���� ��� ��.5,6 �� ������ ��� PEDOT

� ������� de Leeuw�7 ��� ��� Figure 1� ���

��� iron(III)-p-toluenesulfonate ��� EDOT ���� ��� �

����� ���� �� � ��� �� ���� ����� �

�� � �� �� ���� ����. ��� direct oxidative chemi-

cal polymerization ��� �� � �� � 550 S/cm� ��

������ ��� PEDOT� ��� ��.9

� ����� � � iron(III)-p-toluene sulfonate� ��� �

���� �� EDOT� �� � ��� ���� ����

������ �� �� � ���� �� ���� ���� �

��� PEDOT� ���� ��� ��� ��� ���� �

� ����. ���� ���� ��� ���� ������

�� ��� MacDiarmid � Epstein� �� ������, camphor-

sulfonic acid� �� polyaniline(PAni-CSA)� ����� m-cresol

� ������ ������ ���� ��� ��.8 ����

������ m-cresol� ���� � , ��� polyaniline ����

������ �� polyaniline ���� random coil�� extended chain

�� ��� ��� ��� ring twisting �� � conjugation defect�

���� ���� ���� ���� ������ ���

�� ��� ��. �� PEDOT-PSS� �� ���� �

��� dimethylene sulfoxide(DMSO)� ���� � �, ��� ��

� PSS ��� Coulomb interaction� DMSO� ������� PEDOT

� �� ��� ��� ���� �� ������ ����

� ��� ��� ��.10

� ����� �� � ��� ��� ���� ����

�����, ���� ����� �� ������ ���� �

� ����. � ����� � ��� ��� �� ����

���� ������, ��� ���� ��� �� ���

��� ��. �� �� ���(EtOH)� � �(Acetone)� ��

� � ���� 24.3� 20.7� ��� �� ���� ��

�� 280 K��� ������ 19.5� 5.0�10-7 S/cm� � �

� �� ����. ��� Fe(OTs)3� ��� PEDOT ���

���� ���� � �� ������ �� �� �� �

� ��� ����, �� � X� ��(XRD)� X� ���

���(XPS)� ���� �� �� � ��� ��� �����.

2. ��

2.1 ��

���� � Bayer��� ���� 3,4-ethylenedioxythiophene

(EDOT)� ���� ���� � �����, ��� � ���

(dopant)�� iron(III)-p-toluenesulfonate(Fe(OTs)3, Baytron C, 40% solution

in n-Butanol, Bayer)� ��� ���� ��� �����. ���

�� � p-toluenesulfonate� tosylate��� ��� ��� ���

��� � ���� iron(III)-p-toluenesulfonate� Fe(OTs)3� ��

���. ��� ��� ���� ���� ���� �� �

���, ���� ���(MeOH), ���(EtOH), n-���(n-BuOH),

��(hexanol)� �����, ���� � �(acetone), methyl-ethyl-

ketone(MEK)� �����. ��� ���� �� Aldrich Co.�

� ��� ������ � ���� Table 1� �.

2.2 ��� ����������

Fe(OTs)3� ���� �� EDOT� ����� ��� �. �

Fe(OTs)3� ���� 20/20� ����� ��� � ���� 1

� ���� EDOT ���� ���� EDOT/Fe(OTs)3� ���

� 1/2� �� ���. EDOT, Fe(OTs)3 in n-BuOH, ���� �

�� 1/20/20�� ��� ��� � �� 24�� �� ��� �,

�� �� 80 �� �� 12�� ���� �����. ���

�� ��� PEDOT� ��� �� �� ��� ��� �

���� ������, 60 � ������ ����. �� ��

��� PEDOT� �� ��� � ��� ��� ���� �

� � � ��� ������ �� 120 � ������ 3��

�� � �����.

2.3 ������

�� ������ ��� ���� ��� ����� � 4

���(four-probe method)� �����. ����� � � ���

��� ������ � 100 µm� ��� �� ��� ����

�� ����(Dotite XC-12, Fujikura Kasei Co.)� ���� ���

��. Electrosource Meter�� Keithley 2400 SMU� ����� Janis

Table 1. Conductivity at 280 K, T0 from the Temperature Dependency of Conductivity, and Properties of the Selected Solvents

Sample σ(280 K) (S/cm) T0 ε(solvent) B.P.(�, solvent) PEDOT-OTs-MeOH 19.5 1.7�103 32.7 64.7 PEDOT-OTs-EtOH 9.32 2.0�103 24.6 78.3

PEDOT-OTs-Pristine 3.64 7.4�103 17.5 118 Alcohol series

PEDOT-OTs-Hexanol 9.24�10-2 1.0�105 13.3 157 PEDOT-OTs-Acetone 5.0�10-7 1.8�107 20.7 56.1

Ketone series PEDOT-OTs-MEK 2.2�10-9 2.0�107 18.8 72.1

Figure 1. Chemical structure of EDOT, Fe(OTs)3 monomer, and PEDOT-OTs.

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Iron(III)-p-toluenesulfonate� ��� Poly(3,4-ethylenedioxythiophene)� ������ �� ���� �� 365�

Polymer(Korea), Vol. 29, No. 4, 2005�

�� Cryogenic system� ���� 80 K�� 280 K�� �� �

��� ������ �����. ��� ��� ���� ���

PEDOT ��� � ������ � �� 4����� ���

�� �� dielectric analyser(Novocontrol, GmbH)� ���� 280 K

�� 0.1 Hz�� ������ �����, �� �� �����

� ����� �����.

� ����� ��� PEDOT-OTs ��� X-ray diffracto-

meter(X'pert-pro MRD, phili���� ��1.524 Å)� ���� ����

����, 2 θ� 3°�� 30°�� ���� �����.

�� PEDOT� tosylate(OTs ion)� ��� � ���� X-

ray photoelectron spectroscopy(ESCA2000, VG microtech)� �� ��

���. ��� � �� ��� 1�10-9 torr���, X� ���

�� ��������� ������������1486.7 eV)� ���� � ��

� �� C(1s), O(1s), S(2p)� ���� �����.

3. �� � ��

3.1 ���������

Figure 2� ��� ��� PEDOT-OTs-Pristine� �� ��

�� ���� ����� �� ����, � �� �� ��

� �� ��� ���� �� ����. ����� ���� �

��� ��� ��� �� ��� �� ���� ����� �

�� �����. �, ��� �� ���� � ��� �

�� ��� ��� �� �����, ��� ����� � �

��(localized)� ���� � ���� ��� �� �� �

� ��� ��� ��� ����. ��� ���� ��� �

�� ��� ��� ��� �� �(hopping motion)�� ���

� ��.10-12 Mott� ���� � ��� �� ��� �� �� �

�� �� ���� � ����� ��� � ��� ��

��� ���� � ����, �� � � ���� �����

variable range hopping(VRH)� �� ������ ���. �� �

� �� � ���� ��� �� ��� ��� ��

�, ��(phonon)� �� �� ���� ������ �� �

�� ������ ���� ��. ��� ��� �� �� �

��� �����. n�� VRH �� � (1), (2)� ���.11,12

−=

+ )1n/(1

00 exp

T

Tσσ (1)

3FB

0)(

18,where

LENkT = (2)

��� kB� � ��, N(EF)� �� �� �� ��, L

� ��� ��� ����. � (2)�� T0 �� ��� L �� �

�� ���, L� ��� �� �� � �� ��� ��

� ��. ��� ��� ���� �� �� �� �� ����

� ‘metallic islands’� ����� � �� ���� ‘insulating

islands’� ��� � , ‘metallic islands’ ��� �� ��� ��

�� �� (fluctuation-assisted tunneling)�� ����� ���� �

�� Sheng� ����. �� � (3)�� ���, ��� Tt� ��

� ����� ���, ‘metallic islands’ ���, ��� ��

��� � � ��� ��� �� thermal voltage fluctuation�

���� ���. Kivelson �� �� � ��� ��� �� �

�� ����� � � ��� ��� ��� ����� ���

�� �� ������ � � ���� polyacetylene� ���

� � ���. � �� Power law� ��� � (4)� ���� �

� ��. � n>10��� ��.

+

−=s

t0 exp

TT

Tσσ (3)

10nwhere,n >∝ Tσ (4)

Figure 2� (d)�� � �� Kivelson �� log-log plot� ��

�� ��� �� Kivelson �� ���� 10�� � ��(n�

1.406), Power law� ���, �� ����� 0.01437��. ��

Sheng �� 1�� VRH �� � 0.02877� 0.00868� �

���� �����, 0.00547� �� �� ����� � 3��

VRH �� PEDOT-OTs-Pristine� ���� ��� �� � �

���� � ��. � ���� �� �� PEDOT-OTs ���

� ��� �, �� 3�� VRH �� �� �� ���� �

�� ���� � �� Figure 3� ����. Mott� 3�� VRH

�� ���� �� T0 �� Table 1� ����. ����

��� PEDOT- OTs-MeOH ��� � �� ��� � � L�

� �� ��� �� �� � �� ��� �� ��� ��

� ���� ��� �� �� � ��. ��, n-���� �� �

�� PEDOT- OTs-Pristine� � ��, ���� ���� ���

Con

duct

ivity

[S/c

m]

� ������������������������������

Temp-1/2[K-1/2]

(a)

���

����

Con

duct

ivity

[S/c

m]

� ��� ���� ���� ����� ���� ����

Temp-1/4[K-1/4]

(b)

���

����

Con

duct

ivity

[S/c

m]

� ���������������������������������

Temp-1[K-1]

(c)

���

����

Con

duct

ivity

[S/c

m]

� ���� ��� ����

Temp[K]

(d)

���

����

Figure 2. Model-fitting plots of conduction mechanism for PEDOT-OTs-Pristine; (a) One-dimensional VRH model, (b) Three-dimensional VRH model, (c) Sheng model, and (d) Power law.

Page 4: ˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1 iron(III)-p-toluenesulfonate EDOT direct oxidative chemi-

366� �������������������

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��� �� ������ ��� � ��� � 1 �� �� �

�� �� ���, ��� ��� � � � 1�� �� �� �

� ����, ��� �� ����� ������ ��� �

��� ���� �� ���� �� ���. Fe(OTs)3� ��� �

� ���� PEDOT� 550 S/cm� �� ���� ��� ���

��, � ��� ��� PEDOT� � � ��� �� ��� free-

standing ��� ���� ��� �� � ���� �� ���

���. Figure 4�� � �� ��� ��� ��� �� 10-6

S/cm ��� �� ������ ��� ��.

Zabrodskii �� � (5)� ��� reduced activation energy, W� �

��� �� ��� ����� ����, � ��� �� ��

��� � � ��� ���.11-13 ���, Figure 5�� ��� ��

�� ‘0’� ��� �� ���� � ���� ���� �� ��

� PEDOT-OTs � PEDOT- OTs-Pristine ���� ��� ���

��� ��� ����. �� J. Joo �� �� �� ���� PSSA

� �� PEDOT�� ‘0’� ��� �� ��, PSSA�� Fe(OTs)3

� PEDOT� ��� ��� ��� �� ���� ��.10

W(T)�d lnσ(T)/d ln T (5)

3.2 �������

��� ���� ���� ��� PEDOT-OTs � �� X

� �� �� Figure 6� ����. ��� ��� � ��� �

�� �� ��� �� ���� ��� �� � ��� �

��, ��� ��� �� PEDOT-OTs-acetone� PEDOT-OTs-

MEK� �� ������ � �� �� ��. ��, Figure 7�

� K. E. Aasmundtveit ��14 ��� �� �� ��� PEDOT-OTs

� � � � ��� ������, � ��� PEDOT-OTs-Pristine

��� �� Bragg’s law� a-�� b-�� ����� ���

��� �. � c-�� ����� � K. E. Aasmundtveit ��

��� �� ��� �����.

a�14.3 Å, b�6.8 Å, c�7.8 Å

(2θ �6.1°) (2θ �25.8°)

PEDOT ���� ���� (100)� (200)� ��� �� ���

�� PEDOT-OTs� ��� � ���� ���� ����, �

�� PEDOT ��� ��� �� ��� ���� (020)� 2 θ� �

� � �� ��� �� PEDOT ��� ��� ��� � ���

Figure 3. Three dimensional VRH model plots for temperature dependences of the DC conductivity of PEDOT-OTs synthesized with alcohol solvents.

���

���

���

����

����

����

�����

σ [S

/cm

]

� ����� ����� ����� ���� ���� ����

Temp-1/4[K-1/4]

Figure 4. Three dimensional VRH model plots of PEDOT-OTs synthesized with ketone solvents.

����

���

���

����

�����

σ [S

/cm

]

� ����� ���� ����� ����� ����� �����

Temp-1/4[K-1/4]

Figure 5. Reduced activation energy : W-plot.

���

���

����

W(T

) �d

ln σ

(T)/

d ln

T

���� ��� ���� ��� ���

Temp[K]

Figure 6. X-ray diffraction patterns of selected PEDOT-OTs synthesized with various organic solvents. (a) PEDOT-OTs-MeOH, (b) PEDOT-OTs-EtOH, (c) PEDOT-OTs-Pristine, (d) PEDOT-OTs-Acetone, and (e) PEDOT-OTs-MEK.

Inte

nsity

(A.U

.)

�� � ��� �� ��� �� ��

2 θ [°]

Page 5: ˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1 iron(III)-p-toluenesulfonate EDOT direct oxidative chemi-

Iron(III)-p-toluenesulfonate� ��� Poly(3,4-ethylenedioxythiophene)� ������ �� ���� �� 367�

Polymer(Korea), Vol. 29, No. 4, 2005�

� �� ��� ������ ��� �(inter-chain hopping)� �

����� � ��. Figure 6�� PEDOT-OTs-Pristine <PEDOT>

OTs-EtOH < PEDOT-OTs-MeOH� ��� 6° �� 12° �� 2 θ� � � ��� �� �� ������ �� ��� ���� �

��� ���. �� ��� ��� ��� ����� ���� 26°

�� 2 θ� �� ������ ��� 26° �� � � ��

� �� �� �� �� PEDOT-OTs-MeOH� PEDOT-OTs-Pristine�

� ��� PEDOT ��� ��� �, ���� ��� ��

� ��� ������ � � ��.

3.3 ������

XPS ��� � S��� 2p �� �� �� Figure 8� ��

��. ���� ��� Fe(OTs)3� �� �� Fe�� �� �

���� �� �, Figure 1� ��� � � ��� PEDOT-

OTs ��� ��� �� ��� EDOT(C6H6O2S)� ��� �

tosylate(CH3C6H4SO-3)� ��� S��� � ��� PEDOT

� S��� 164 eV ���, tosylate � � S ��� 168 eV �

�� � ���� ��.15 �� �� �� Fe(OTs)3� ����

��� Figure 8� (d)� � , ��� Fe(OTs)3� S��� �� �

���� ��� S ��� 2p �� � ���� 168.9 eV��.

Figure 8� (a), (b), (c)� PEDOT-OTs-Pristine, ���� �� �

�� PEDOT-OTs-MeOH, � �� �� ��� PEDOT-OTs-acetone

��� �����. ��� ����� (d)� �� 164 eV�

� ��� ��� � ���, �� PEDOT� � ���� �

��. 164 eV� � ��� ��� ���� spin-split doublet�

S(2p3/2)� S(2p1/2)��. �� PEDOT� ���� Fe(OTs)3� ��

�� PEDOT-OTs(S-3PEDOT+)� ��� �� � S(2p)� � �

��� 167.4 eV� � � ��. G. Zotti �� XPS �� �� PEDOT

� PEDOT-OTs ��� � ��� ��(binding energy shift)�

3.4 eV�, PEDOT-OTs� tosylate ��� � ��� ��� 1.5 eV

� ���� ������, �� � ��� �� ��� ���

�.16-18 �� (c) PEDOT-OTs-acetone ��� XPS �� �� (a) PEDOT-

OTs-Pristine�� (b) PEDOT-OTs-MeOH �� �� ��� �

� tosylate� ��� �� PEDOT� �� ���� PEDOT-OTs

� S(2p)� ��� ��� �� ��, 169 eV �� tosylate�

164 eV �� ���� PEDOT� S(2p)� ��� �� �� �

� � ��. PEDOT-OTs-acetone ��� � �� ��� ��

��� � � PEDOT� PEDOT-OTs ��� ��� ��� �

� ���� ��� � ��� � � ��. �� ��� ���

� ����� ��� ����� � �� �� OH�� ��

�� ferric � (Fe3+)� �� ���� ���� ���� �

� ��, � ��� OH�� �� ��� � �� �����

���� �� ������ ��� ��� ����.

4. ��

Iron(III)-p-toluenesulfonate� ��� � ���� �� EDOT� �

� � �� �� ���� ���� ������ ����

���. ��� ���� ��� ���� ����� ���

Figure 7. Structural model of PEDOT-OTs, in projections along b (upper) and along c (lower). This structure is quoted from K. E. Aasmundtveit et al.14

Figure 8. Selected and fitted XPS results : each S(2p) signals of (a) PEDOT-OTs-Pristine, (b) PEDOT-OTs-MeOH, (c) PEDOT-OTs-acetone, and (d) Fe(OTs)3 for comparison.

Inte

nsity

(A.U

.)

���� ���� ���� ���� ���� ���� ���� ����

Binding energy(eV)

Page 6: ˘ ˇ - CHERIC · 364 , 29 4 , 2005 , OLED . PEDOT-PSS 10 S/cm .5,6 PEDOT de Leeuw 7 Figure 1 iron(III)-p-toluenesulfonate EDOT direct oxidative chemi-

368� �������������������

���, �29� �4�, 2005� �

� ���� � �� ������ PEDOT-OTs-Pristine(in n-BuOH)�

����� ��� �� ��� � 1 �� �� ���� �

� �����. ���� �� ��� PEDOT-OTs ��� ���

� � ���>���>���(Pristine)>��� ��� �� �

� ������ ��, ���� ��� ��� ����� ��

� ��� �� ��� ���. ���� ���� ��� PEDOT-

OTs� ����� ������ ���� ��� ��� ��, �

��� ���� ��� PEDOT-OTs� � �� ������

���. ��� �� ������ ����� �� Mott� 3

�� VRH �� ��� PEDOT-OTs ���� �� ��� �

� ������, reduced activation energy� ��� W-plot� ��

� ���� ��� ��� ��� ��� � � ��. ��

� ���� �� � �� ������ � �� ��� �

� XRD� �� PEDOT� �� ��� ��� �, ��� �

��� ��� �� ���� ��, ���� ��� PEDOT-OTs

���� ���� ������ �����. �� �� ���

� ��� � � PEDOT ��� ��� ����� �� ���

�� ������� �� ��� ��� ����� ��

��� ��� ��� ����. ��� �� ��� ��� �

�� � � X� ������� �� ���� PEDOT�� �

�� ���� �����. S(2p) ��� ��� � ����

���� PEDOT� tosylate � ��� ���� ����, �

��� ��� ��� PEDOT-OTs� ���� ���� PEDOT�

�� ���� � � ��. �� ��� ���� ��� PEDOT

� ��� ��� �� ��� ��� ���, ���� inter-

chain hopping conduction� ��� �� �� � ��� ����.

��� ��� ��� �� ������ ��� PEDOT� �

�� � p-toluenesulfonate� ���� ������ �� ��

� ��� ���� ��� �� PEDOT� ��� � ��

���� ���� ������ ���� �� �����.

����

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