Electroluminescence Characteristics of Blue Light Emitting Copolymer Containing Perylene and Triazine

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Polymer (Korea), Vol. 28, No. 5, pp 367-373 (2004) /

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Electroluminescence Characteristics of Blue Light Emitting Copolymer Containing Perylene and Triazine

Moieties in the Side Chain

Chang Ho Lee, Seung Hoon Ryu, Hwan Sool Oh*, and Se Young Oh^% Department of Chemical & Biomolecular Engineering, Sogang University,

1 Shinsoo Dong, Mapo Gu, Seoul 121-742, Korea

*Department of Electronics Engineering, Konkuk University, 1 Hwayang Dong, Gwangin Gu, Seoul 143-914, Korea

†e-mail : syoh@sogang.ac.kr

(Received March 2, 2004;accepted August 12, 2004)

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©ô¼ ©q˜@$. \°œ 5Q©ôÔ ´œœä`, THF, ´œœ,Ä, ä`< Y€ ¼X `p é$ $ð Ø ¹˜$. Dq lÅ D9 (ITO)/ 5Q©ô / Œ(8Ä|œ ¬q\ (uU `p \Q ÌÐÔ 5Q©ô

\ ø섘 ¨` ´ 30%¼ Œ Ðìô U´ Ø ˜ œ ˜ ¸À ÑÐ èh (0.003%)„ Ø ô

$. ùÈ D\ \ќ `p \Q ÌÐÔ ØôL \Qô
‘˜Ô í \Q (479 nm)„ Ø $. ¬

 D•€ 5 Vœ $ð î˜ , ÌœÔ X R´ 0.16, Y R´ 0.17´$.

,-897,.9¹Novel non-conjugated blue light-emitting copolymers containing perylene and triazine moie- ties as light emitting and electron transporting units, respectively in the polymer side chain were synthe- sized. The resulting copolymers were soluble in most organic solvents such as chlorobenzene, THF, chlo- roform and benzene. The single-layered electroluminescence (EL) device consisting of indium tin oxide (ITO)/copolymer/aluminium (Al) exhibited a maximum external quantum efficiency (0.003%) and a good carrier balance when the triazine content was 30%. In particular, the device emitted blue light (479 nm) corresponding to the emission of perylene moiety. The drive voltage was observed at 5 V and the CIE coor- dinate was x¼0.16, y¼0.17.

Keywords¹blue light-emitting copolymer, electron transporting unit, single-layered EL device, carrier balance, drive voltage.

  Lee et al. Polymer (Korea), Vol. 28, No. 5, 2004/

  ´}x# 1# žVâ, \28Ì \5x, 2004„/

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;ú1 ( ô˜ ©q ½ Q\ N-bromosuccinimide, potassium carbonate, tetrakis(triphenylphosphine)palladium, triethylamine€ Aldrich Chem. Co.˜ ùI ½„ U\ <

U ´ ìé˜@ , methacryloyl chloride, triethylamine, perylene, 4-aminophenylboronic acidÔ Tokyokasei Co.˜ ù I ½„ ¬Å˜, U\ <U ´ ìé˜@$. ©q é$œ ìéœ THF, ä`, ”l< ´œœ,Ā J. T.

Baker˜ ùI ½„ ìé˜@ , Q© \\œ ìéœ

AIBN€ Junsei Chem. Co.˜ ùI ½„ ìé˜@$.

30^I0+shu|ohq060|o,skhq|o`phwkdfu|odplgh#A F1Õ#æ®1 U5 D, O í \Q ùq„ VÔ per- ylene moiety¼ ,¨˜Ô methacrylamide ( ô˜ ©q

€ 3( X‘|œ ɘ@$ (Scheme 1). 3¬ ¥< L

¼ä¬ $ôÈÔ THF é$ perylene 4 g (16 mmol)

< N-bromosuccinimide 2.82 g (16 mmol)„ c 24D

ˆ
h\ Xè$. L¬” X‘´ Å\  X

‘ |©|„ | A˜è $Œ Xè$. q\ ¨ D|„ ,<è $Œ 5˜\ ´°è  ´œœ

,Ä é$œ ìðU˜, 5 g (94%)˜ U\\ 3-bromo- perylene„ û$.  È& (˜ X‘ <U€ $Œ<

Y$. Potassium carbonate Xé¡ 10 mL (1 M)„ 3- bromoperylene 2.3 g (7 mmol)< 4-aminophenylboronic acid 1.2 g (7 mmol)˜ THF é¡(300 mL) c Xè$.

´ |© é¡ 30 mg˜ tetrakis(triphenylphosphine)palladium

´ ¨`\ THF é¡ 5 mL¼ A˜ä 24D ˆ

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lœ xÙè  5˜\ 12D ˆ ´°è$.

œÅA|œ ´œœ,Ä é$¼ ìé˜, ìðU ˜´

¸À ˜ p-(perylene-3-yl)phenylamine˜ Ä„ û$

(1.9 g, Xh 81%).  (˜ X‘€ methacryloyl chloride 0.6 g´ $ôÈÔ ä` é¡ 10 mL¼ p-(perylene-

Br O N O

Br

(HO)2B NH2

NH₂

NH

CH₃ C C Cl

CH2 O

CH₃ C C

CH₂ O

+

Br

NH2

+

Pd(PPh₃)₄

+ ^C6H15N

r.t.

THF

THF

benzene Br

O N O

Br

(HO)2B NH2

NH₂

NH

CH₃ C C Cl

CH2 O

CH₃ C C

CH₂ O

+

Br

NH2

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+ ^C6H15N

r.t.

THF

THF

benzene

 6FKHPH  Synthetic route of N-[p-(perylen-3-yl)phenyl]meth- acrylamide.

Polymer (Korea), Vol. 28, No. 5, 2004_ Blue Light Emitting Copolymer _{ }



žVâ, \28Ì \5x, 2004„ í \Q 5Q©ô˜ Dp\Q ùq# #

3-yl)phenylamine 1.9 g (5.7 mmol)< triethylamine 0.6 g (5.9 mmol)´ ¨`\ ä` é¡ (500 mL) 10 ˜\ A

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Ì Ä] ð<Ô $Œ< Y$. ¹H NMR (500 MHz, CDCl3/G+G+P+

(m, 3H), 5.821 (s, 1H), 5.493 (s, 1H), 2.065 (s, 3H); FT-IR (KBr, cm^-1): 3426, 3156, 3048, 2950, 1882, 1783, 1611, 1583, 1537, 1442, 1388, 805, 762, 703; Calculated C: 87.1%, H:

5.6%, N: 3.4%, O: 3.9%; Found C: 87.5%, H: 5.1%, N: 3.4%, O: 4.0%.

DÐ D,ô N-[p-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]

methacrylamide ( ôÔ ´D 4 œ iÕ ˜´ © q˜@$.¹⁶

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Table 1 PPPMA-co-DTPM 5Q©ô˜ Xh< X ÄÐ ˜ ð<¼ Ø ô$. 5Q©ô˜ Xh< X ÄÐ €  ( ô˜ 5I „h
@´ 75%

€ X ÄÐ 7200 D¼ Ø ô$. ´,œ ð<

Ô U5 D, åe„ VÔ PPMA í \Q ( ô€

DÐ D, åe„ VÔ DTPM ( ô˜ ¼T¼ Q© œ q´ „÷˜p Œx¸ Ã|œ A\$. p¼\  ( ô˜ 5I „h„ °H˜, q\ 5Q©ô˜ U5 O DÐ Ðìô˜ D, U„ \`äp D˜, 5Q

©ô˜ „h„ °H˜@$.

Figure 1 PPPMA-co-DTPM 5Q©ô˜ ¹H-NMR ä Ùø<„ Ø ô$. 5Q©ô˜ äÙø<\ ( ô

˜ „ 89 ´9XÔ 5ð6 ppm˜ ùq |¬@ „D È ì¼ Ã|œ 4„ Q©´ É\ Ä •¸  X È

$.

Figure 2(a)Ô THF é¡ ˜\ DTPM˜ 5I ¨`

 p¸ PPPMA-co-DTPM 5Q©ô˜ PL äÙø< ð<

´$. DÐ D,ô DTPM `ø˜ 5I ¨`  p¸

5Q©ô˜ œ PL |¬Ô PPPMA ( ÄИ ý ð 473 nm, 20%¼ Œ 464 nm, 30%¼ Œ 460 nm€ 40%

7DEOH1XPEHU$YHUDJH0ROHFXODU:HLJKWDQG<LHOGRI

3330$.4'730XQGHU9DULRXV0RQRPHU5DWLRV  sam p le

N o

P P M A :D T P M feed ratio s

n u m b er av erag e m o lecu lar w eig h t (M n )

y ield (% )

1 1 .0 : 0 8 0 0 0 8 0

2 0 .8 : 0 .2 7 2 0 0 7 5

3 0 .7 : 0 .3 7 3 0 0 7 5

4 0 .6 : 0 .4 7 1 0 0 7 5

  Lee et al. Polymer (Korea), Vol. 28, No. 5, 2004/

  ´}x# 1# žVâ, \28Ì \5x, 2004„/

¼ Œ 461 nm¼ Ø ô$. ´€ Y´ 5Q©ô˜ PL λmax R€ DTPM ¨` ´ Ý@ X (Lå|œ ´

X 30% ´
\Ô 8,œ ýå´ ,”XÔ Ã„ Œ

X È$. ´,œ Q™A ùq˜ ð<¼ À” ÐxÈ

„ Àà˜p D´ PPPMA ÄÐ DTPM ( ô

@ QDpA œq´ Ô methyl methacrylate ( ô

¼ Ŝ PPPMA-co-MMA 5Q©ô¼ ©qœ  Y

€ é$ ˜\ MMA˜ ¨`  p¸ PL ùq˜

”¼ °ì˜@$. ´ ð<¼ Figure 2(b) Ø ô$.

PPPMA-co-MMA 5Q©ô\ MMA ( ô@ Ô

ýð 3/ max R€ 473 nmœ Ø Ø  MMA ( ô

@ 30% Å\ ýð 467 nmœ (Lå|œ ´X 40%

´
\Ô ° ”@ $. É PPPMA-co-MMA 5 Q©ô\ MMA (Dô˜ 5I ¨` ´ Ý@ X

3/ max R€ (Lå|œ P̘, PPPMA-co-DTPM 5Q

©ô˜ PL ùq< Y€ ð<¼ Ø ô$. PPPMA-co-

DTPM 5Q©ô\ DTPM (DôÔ \Q ùq´ 

ØôL ÄÐD˜ x¼ PÌ\<Ô MMA (Dô

€ `ìœ äh´\ - „ ˜Ô Ã|œ ìd\$. p¼\

PPPMA-co-DTPM 5Q©ô\ DTPM ¨` Ý@

p¼ 5Q©ô˜ PL λmax R´ (Lå|œ ´˜Ô Ã

€ ØôL a ÄÐD˜ °ì@ Ý@˜, Øôð ÄÐ D˜ ¬] è< Œx´¼ A\$. 2œ PPPMA-co-

DTPM 5Q©ô\ DTPM (Dô˜ Å p¼ 5Q

©ô˜ a ÄÐD˜ ÅôA è< ˜´ ÄÐ ìì

˜ U@ ôKØÔ ¬°¼ @ Ì Xô a ÄИ

´q´ Ø  ð<A|œ PL λmax R€ T( ´´

XÔ Aå ÈÔ Ã|œ A\$.

Figure 3 ITO/PPPMA-co-DTPM/Al|œ ¬q\ `p

\Q ÌИ EL äÙø<„ Ø ô$. ´D˜ PL ä Ùø<˜ ð<€ l@ œ œ EL |´¬Ô DTPM

˜ 5I ¨` ´ Ý@ X P̘, 20%¼ Œ 491 nm, 30%¼Œ 480 nm 8ì 40%\ 479 nm¼ Ø ô

$. ´€ Y€ EL ùq˜ ”Ô 5Q©ô ììô˜

)LJXUH PL spectra of (a)PPPMA-co-DTPM and (b)PPPMA- co-MMA in THF at various copolymer ratios.

#633# 683# 733# 783# 833# 883# 933# 983# :33#

Wavelength (nm)

(a)

414 413 31<

31;

31:

319 318 317 316 315 314 313

Intensity (a.u.)

0 1 2 3 4 5 6 7 8 9 0 1

0.6 : 0.4 (461 nm) 0.7 : 0.3 (460 nm) 0.8 : 0.2 (464 nm) 1.0 : 0.0 (473 nm)

0 1 2 3 4 5 6 7 8 9 0 1

0.6 : 0.4 (465 nm) 0.7 : 0.3 (467 nm) 0.8 : 0.2 (472 nm) 1.0 : 0.0 (473 nm)

#633# 683# 733# 783# 833# 883# 933# 983# :33#

Wavelength (nm)

(b)

414 413 31<

31;

31:

319 318 317 316 315 314 313

Intensity (a.u.)

/ /

)LJXUH ¹H-NMR spectrum of PPPMA-co-DTPM copolymer.

633# 683# 733# 783# 833# 883# 933# 983# :33#

Wavelength (nm) 414

413 31<

31;

31:

319 318 317 316 315 314 313

Intensity (a.u.)

0 1 2 3 4 5 6 7 8 9 0 1

0.6 : 0.4 (479 nm) 0.7 : 0.3 (480 nm) 0.8 : 0.2 (491 nm) 1.0 : 0.0 (491 nm)

)LJXUH  EL spectra of ITO/ PPPMA-co-DTPM /Al devices under various copolymer ratios.

# <# ;# :# 9# 8# 7# 6# 5# 4# 03# ssp#

4# # 6#

vroyhqw#

Polymer (Korea), Vol. 28, No. 5, 2004_ Blue Light Emitting Copolymer _{ }



žVâ, \28Ì \5x, 2004„ í \Q 5Q©ô˜ Dp\Q ùq# #

ØôL ÄÐD˜
xÑé´ Ñ„ p Œx¸ Ã|œ

AX ùÈ PL ùq˜ ð<€ l@ œ DTPM˜

5I ¨` ´ 30% ´
\Ô ° ”@ $.

PPPMA- co-DTPM 5Q©ô˜ EL ð<\ DTPM (Dô@ 5Q©ôô\ äØ´\ - „ ´<Ô Ã

„ •¸  X È$. ð< A|œ 8 0¬\ ©q

œ PPPMA-co-DTPM 5Q©ôÔ DÐ D, åe„ V Ô DTPM (Dô@ 5Q©ô\ äØ´\ - „ ˜ , \Q ùq\ ¬] è<€ ÅôA Aå 1 ˜

´ 4$ LÀ  @Œô (Lå˜ ›„ ôÔ Ã„ Œ X È$.

`p \Q ÌИ ¬ D•< èh€ ìéXÔ `p

|< D9˜ ¼œ åý ˜´ ¬Ì ÌðXÔ Ã„ Œ X È$.¹⁹ ùÈ ´
A¸ D9„ ìéœ `p \Q Ì Ð˜ ¬ D•€ U5 O DÐ D,u |˜ HOMO

€ LUMO @D ˜´ ðUXô$. ITO/PPPMA-co- DTPM/Al|œ ¬qXÔ `p \Q ÌИ H $´

„8è„ Figure 4 Ø ô$. 5Q©ô˜ HOMO€

LUMO˜ H @DÔ cyclic voltammetry€ UV-Vis. a U ˜´ û$. 5Q©ô˜ H @DœÀp Œ X È/´ PPPMA ÄÐ DÐ D, åe„ VÔ øì

„ ( ô¼ Ũ|œ¨ U5˜ <Å  „

¼ DИ <Å 鴜 Ä Œ X È$. ITO D9

\ ØôL moietyœ U5´ <ÅX Al D9|œÀp øì„ moietyœ DÐ@ <Å\$. <Å\ D˜Ô U 5 D, åe„ VÔ ØôL a ÄЀ DÐ D, å e„ VÔ øì„ a ÄÐD|œ x‘ ˜œ inco- herent <U|œ ´\$.

ITO/PPPMA-co-DTPM/Al|œ ¬qXÔ `p \Q ÌÐ

˜ D˜-D• ùq„ Figure 5 Ø ô$. Figure 5

\ Œ X È/´ ÌИ ¬ D•€ 5Q©ô˜ „h

 ¬Ì ˜´˜@$. ùÈ œ ˜ D˜-D• ùq€ 5 Q©ô\ DTPM˜ 5I ¨` ´ 30% (7:3 „h)¼

Œ Ø ô$. ´,œ ð<œÀp PPPMA-co-DTPM 5 Q©ô˜ „h´ 7:3¼ Œ D˜ D,˜ U ùq´ @ å 0ôÜ Ã„ Œ X È$. É 5Q©ô\ ØôL ÄÐD˜ U5 ´@ øì„ ÄÐD˜ DÐ ´

4$  ´p Œx ø섘 ¨` ´ 30%¼ Œ D˜ D, U´ Ø Ô Ã|œ ìd\$. ùÈ PPPMA-

co-DTPM 5Q©ô¼ ìéœ ÌИ ¬ D•€ 5 V

˜ $ð î€ R„ 4@$. ´€ Y´ PPPMA ÄÐ

DTPM˜ (Dô¼ Ũ|œ¨ Ðìô˜ U „

¼ D˜-D•˜ DpA ùq $ð ¬Ì å
XÔ Ã

„ Œ X È$.

Figure 6€ ITO/PPPMA-co-DTPM/Al|œ ¬q\ `p

\Q ÌÐ\ ( ô˜ 5I „h p¸ ¸À ÑÐ è h˜ ”¼ Ø ø ô$. ÌИ ÑÐ èh€ DTPM



)LJXUH Schematic energy diagram of ITO/PPPMA-co-DTPM/Al device.

3# 4# 5# 6# 7# 8# 9# :#

Voltage (V) 613#

518#

513#

418#

413#

318#

3#

Q.E. (10-3 %)

4 3 3 3 3 3

0.6 : 0.4 0.7 : 0.3 0.8 : 0.2 1.0 : 0.0

)LJXUH  External quantum efficiency of ITO/ PPPMA-co- DTPM /Al devices under various copolymer ratios.

3# 4# 5# 6# 7# 8# 9# :# ;#

Voltage (V) 313363

313358 313353 313348 313343 313338 313333

Current (A)

0 5 0 5 0 5 0

0.6 : 0.4 0.7 : 0.3 0.8 : 0.2 1.0 : 0.0

)LJXUH  Current-voltage characteristics of ITO/PPPMA-co- DTPM/Al devices under various copolymer ratios.

  Lee et al. Polymer (Korea), Vol. 28, No. 5, 2004/

  ´}x# 1# žVâ, \28Ì \5x, 2004„/

˜ 5I ¨` ´ 30%¼ Œ @å Ҁ 0.003% R„ Ø ô$. ´€ Y€ ð<Ô ÌИ I-V ùq ð<\

€ l@ œ PPPMA-co-DTPM 5Q©ô˜ „h´ 7:3

\ Ðìô˜ <Å O Xá´ @å Ë|° Ðìô U 2œ Ø p Œx¸ Ã|œ A\$. ùÈ D\

\°œ `p \Q ÌÐÔ DC 10 V\ 200 cd/m²˜ ]

€ í \Q„ Ø ô$.

ÄÐ \Q $´d˜ ¬ ”$؀ ¼XA|œ

triangular åý„ õœ D \Q ˜œ tl
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)LJXUH Fowler-Nordheim plots of Au/PPPMA-co-DTPM /Au devices under various copolymer ratios.

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)LJXUH CIE chromaticity diagram of ITO/PPPMA-co-DTPM (7:3)/Al devices.

Polymer (Korea), Vol. 28, No. 5, 2004_ Blue Light Emitting Copolymer _{ }



žVâ, \28Ì \5x, 2004„ í \Q 5Q©ô˜ Dp\Q ùq# #

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