PACS numbers: 42.15.Eq, 42.79.Kr

Simulation Study on the Outcoupling Efficiency and Intensity Distribution of Photonic Crystal-based Organic Light-emitting Diodes

Su Seong Jeong · Hyun-Woo Choi · Jae-Hyeon Ko ^∗

Department of Physics, Hallym University, Chuncheon 200-702, Korea (Received 30 May 2013 : revised 19 June 2013 : accepted 9 August 2013)

The outcoupling efficiency (OCE) and the intensity distribution for photonic crystal-based organic light-emitting diodes (OLEDs) were investigated by using the finite difference time domain method and a ray tracing optical simulation. The OCE increased by a factor of ∼1.3 when optimized cylindrical photonic crystals, where refractive index was set to 1.9, were formed as a square lattice between the transparent electrode layer and the substrate. The inclusion of scattering particles in the substrate was effective in extracting the substrate mode, by which the OCE could be enhanced by a factor of ∼1.46. The intensity distribution from the photonic crystal-based OLEDs exhibited a four-fold rotational symmetry, which reflected the symmetry of the square lattice structure of the photonic crystals. This peculiar intensity distribution approached the Lambertian distribution as the density of the scattering particles included in the glass substrate was increased.

PACS numbers: 42.15.Eq, 42.79.Kr

Keywords: Organic light-emitting diode, Photonic crystal, Outcoupling efficiency, Simulation, Intensity distribution

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PACS numbers: 42.15.Eq, 42.79.Kr

Keywords: Ä »l µ 1 Ï F  g  s š ¸× ¼, F  g  & ñ , F  g Æ ÒØ  ¦ ´ òÖ  ¦, r Ó ý t Y Us ‚  , F  g • ¸ ì  r Ÿ í

∗

E-mail: hwangko@hallym.ac.kr 892

I. " e  ] Ø

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Fig. 1. (Color online) A cross-section of a bottom- emitting OLED and the distribution of light energy into the air mode, substrate mode, waveguide mode and cou- pling to surface plasmons.

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Fig. 2. (Color online) Cross-sections of (a) the OLED, (b) the SiN-applied OLED, and (c) the photonic crystal- applied OLED studied by the FDTD method. (d) is the top view of the photonic crystal lattice.

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ƒ

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 ™ è _  F  g: £ ¤$ í `  ¦ r Ó ý t Y Us ‚   % i  .

2. S ö o Ú7 _T  Ó Å { ¢¨ | 

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$

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29] \ " f ½ ¨» ¡ ¤ ô  Ç r Ó ý t Y Us ‚   — ¸4 S qõ  l ‘ : r& h Ü ¼– Ð 1 l x{ 9  



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r Ï ã J] X Ö  ¦ 1.66 \  80 nm_  ¿ ºa – Ð, & ñ / B N Å Ò{ 9 8 £ x (HTL)“ É r Ï

ã J] X Ò  ¦ 1.82 \  50 nm_  ¿ ºa – Ð, ITO  H Ï ã J] X Ò  ¦ 1.86 \  150 nm ¿ ºa – Ð, Õ ªo “ ¦ Ä »o   H 1.48 _  Ï ã J] X Ò  ¦ – Ð [ O & ñ 

%

i  . F  g • ¸ì  r Ÿ í\  ¦ S X ‰ “   l  0 Aô  Ç  Ž Ø  ¦ l   H ITO  À »€  “   Ä

»o  5 Å q \  C u ÷ &% 3  . Ä »l µ 1 Ï F  g ™ è \  ¦ à ºì  r õ  / B N l – ÐÂ Ò '

 ˜ Р ñ l  0 AK  ITOü < Ä »o   s \  70 nm ¿ ºa _  SiN

~ Ã

Ì} Œ •8 £ x`  ¦ + þ A$ í ô  Ç ½ ¨› ¸ Fig. 2(b)\  ] jr ÷ &# Q e ” “ ¦ Õ ª 0

A\  F  g  & ñ ½ ¨› ¸ + þ A$ í  ) a ½ ¨› ¸_  ô  Ç \ V Fig. 2(c)\  ]

jr ÷ &% 3  . s  \ V\ " f  H ì ø Ít 2 £ § s  140 nm“   " é ¶: Ÿ x+ þ A SiN s

 Å Òl  500 nm“   & ñ  y Œ •+ þ A     + þ AI – Ð Å Òl & h Ü ¼– Ð C

u ÷ &# Q e ”  . F  g  & ñ ½ ¨› ¸\  ¦ 0 A\ " f   ‘ : r é ß –€  • ¸

Fig. 2(d) \  ˜ Ð# Œt “ ¦ e ”  . ‘ : r ƒ  ½ ¨\ " f  H ETL _  ¿ ºa , F 

g  & ñ ½ ¨› ¸_   € ª œô  Ç   à º[ þ t, 7 £ ¤ f ”  â , Z  } s , Å Òl  1 p x _

 † < Êà º– Ð r Ó ý t Y Us ‚  `  ¦ à º' Ÿ  # Œ þ j& h _  OCE\  ¦ ˜ Ðs 



 H OLED ½ ¨› ¸\  ¦ ¹ 1 ԓ ¦  % i  .

F 

g " é ¶ Ü ¼– Ѝ  H " f– Ð f ” “ §   H [ j ~ ½ ӆ ¾ ÓÜ ¼– Ð ”  1 l x   H Š © œF G



\  ¦ ETL õ  HTL_   â > €  _  ×  æ € © œ\  C u K  1 p x ~ ½ Ó& h  & h  F 

g " é ¶ s  ÷ &• ¸2 Ÿ ¤ % i “ ¦ F  g " é ¶ _    © œ“ É r 550 nm é ß –Ò  oF  g Ü ¼

–

Ð [ O & ñ % i  . FDTD ? /  6   x ) a OLED _  V , s   H 10 × 10 µm

% i “ ¦, # Œl \ " f % 3 # Q”   Ø  ¦F  g ì  r Ÿ í\  ¦ & h 6   x ô  Ç ASAP

?

/  © œ F  g " é ¶ _  €  & h “ É r 0.5 × 0.5 mm

% i Ü ¼ 9 s   © œ F  g

"

é

¶“ É r Ä »o  l ó ø Í_  ×  æ € © œ\   o ¸ ú š€ Œ ¤ . Ä »o l ó ø Í_  €  & h  õ

 ¿ ºa   H y Œ •y Œ • 2 × 2 mm

ü < 0.7 mm– Ð [ O & ñ % i  .

III. S ö o Ú7 _T  Ó Å + s ÇÊ Ý õ m Í ‚ º8 ý

1. SiN U c lT c l X ì Ä “ Ó Þ OLED S ö o Ú7 _T  Ó Å + s ÇÊ Ý

OLED  H Ï ã J] X Ò  ¦ s  " f– Ð   É r  8 £ x _  ~ à Ì} Œ •½ ¨› ¸– Ð ÷ &# Q e ”

“ ¦, ETL_  ¿ ºa \     y n Cs  Ò q t$ í ÷ &  H 0 Au ü < 6 £ §F G   s

_  ç ß –  s     l  M :ë  H \  ³ ð€   e  ¦  Û ¼ 7 H _  # Œl , 6 £ §F G õ

 ITO  s \  + þ A$ í ÷ &  H p ™ è / B N”   ´ òõ  (micro cavity effect) 1 p x _  4 Ÿ ¤ ½ + Ë& h “   ‰ & ³ © œ\  _ K  ’ < Hz  ´s  Ò q t|   . Õ ªA 

"

f ETL_  ¿ ºa \     Ø  ¦F  g ÷ &  H „   l  _  F  g • ¸ ì  r Ÿ í



 H ß ¼>     >   ) a   [1,30]. OLED l ‘ : r ½ ¨› ¸ x 9  # Œl \  í

ß –ê ø Í8 £ x õ  pillow E $ ™Ý ¼ & h 6   x ) a ½ ¨› ¸\  @ /K  ETL_  ¿ º a

 p u   H % ò † ¾ Óõ  › ' aº  K " f  H s p  s „  \  Ø  ¦ ç ß –  ) a  7 H ë

 H [28,29] \ " f  © œ[ jy  [ O " î ô  Ç   e ”  .   " f ‘ : r  7 Hë  H \ 

"

f  H ŠҖ Ð F  g  & ñ ½ ¨› ¸ & h 6   x ) a OLED ½ ¨› ¸ x 9  s  ½ ¨

›

¸_  OCE\  ETL ¿ ºa  p u   H % ò † ¾ Ó\  @ /K   À ғ ¦  ô

 Ç .

Figure 3“ É r SiN ~ à Ì} Œ •8 £ x s  & h 6   x ) a OLED \ " f ETL ¿ ºa 

\

    ITO\  ¦ È Òõ  # Œ Ä »o  l ó ø Í A á ¤ Ü ¼– Ð
“ : r y n C_  -„   l

 © œ [ jl _  ] jY  L \  q Y V   H- " é ¶  o  © œ (far-field) F  g • ¸ ì

 r Ÿ í\  ¦
  · p . ETL 0 A µ 1 Ï F  g8 £ x \ " f f ” ] X  Ä »o \  ¦ † ¾ Ó 



 H y n Cõ  x 9 €  _  6 £ §F G \ " f 180• ¸– Ð 0 A © œs   Ÿ ÷ ¶ Ê ê ì ø Í 

÷

&# Q `  ¦  š ¸  H y n C  s _  p ™ è / B N”   ´ òõ \  _ K  & ñ €  `  ¦

†

¾ Ó   H F  g • ¸_  [ jl  ‰ & ³$ y       H  כ `  ¦ S X ‰ “  ½ + É Ã º e ” 



. ETL_  ¿ ºa  100 nm Â Ò   H{ 9  M : & ñ €  Ü ¼– Ð ˜ Ðy © œç ß – [ O

s  { 9 # Q
€  " f s  ~ ½ ӆ ¾ ÓÜ ¼– Ð  © œ{ © œy  y © œ o  ) a y n C_  [ jl  ì

 r Ÿ í\  ¦ S X ‰ “  ½ + É Ã º e ”   H X < ì ø ÍK , 160 ∼ 180 nm Â Ò   H \ " f



 H  © œ Wç ß –[ O \  _ K  & ñ €   ~ ½ ӆ ¾ ÓÜ ¼– Ð † ¾ Ó   H y n C_  € ª œs  / å L

 

y  ×  ¦ # Q[ þ t # Q e ” 6 £ §`  ¦ · ú ˜ à º e ”  . s  Qô  Ç   õ   H OLED

?

/ ) ‡6   x ÷ &  H • ¸  — ¸× ¼_  > hà º_     oü < › ' aº  ÷ &# Q e ” “ ¦, s

„  \  ˜ Г ¦  ) a r Ó ý t Y Us ‚     õ  [30]ü < & ñ $ í & h Ü ¼– Ð { 9 u 

Fig. 3. (Color online) The far-field intensity distribution of the light emitted from the ITO electrode as a function of the ETL thickness, which was detected in the glass substrate by using the FDTD method. SiN layer was applied to the OLED without photonic crystals.

  H   õ s  . Fig. 4  H Fig. 3 _  F  g • ¸ ì  r Ÿ í\  ¦ ASAP ? /

\

 [ O & ñ  ) a  © œ F  g " é ¶ _  C  F  g ì  r Ÿ í– Ð • ¸{ 9 ô  Ç Ê ê, F  g‚  Æ Ò& h  l

Z O Ü ¼– Ð ½ ¨ô  Ç OLED Ä »o  l ó ø Í 0 A_  F  g • ¸ ì  r Ÿ í\  ¦ ETL _

 ¿ ºa \    
  · p  כ s  . Fig. 3\  ] jr   ) a ITO 0 A Ä

»o  l ó ø Í 5 Å q _  F  g • ¸ ì  r Ÿ í ×  æ €  • 50• ¸ s  © œ_  “ ¦r  y Œ •

`

 ¦ † ¾ Ó   H F  g‚  [ þ t“ É r „  ì ø Í \  _ K  l ó ø Í — ¸× ¼– Ð y Œ —y  9

’

< Hz  ´ ) a  . s – Ð “  K  OLED µ 1 Ú_  F  g • ¸ ì  r Ÿ í  H Ä »o  l  ó

ø Í ? / F  g • ¸ ì  r Ÿ íü <  © œ{ © œy  ´ ú §s   2 £ §`  ¦ · ú ˜ à º e ” “ ¦ l ‘ : r

&

h Ü ¼– Ð “ ¦r  y Œ •`  ¦ † ¾ Ó   H y n C_  q ×  æ“ É r B Ä º  Œ • & ’ 6 £ §

`

 ¦ · ú ˜ à º e ”  . Fig. 5  H ETL _  ¿ ºa \     > í ß –  ) a y n C\ 

-t _  C ì  r q Ö  ¦ s  . À 1 Ïy © œ " é ¶ l   ñ  H y Œ • › ¸| Z >  ü @ Җ Ð Æ

ÒØ  ¦ ) a OCE _  q ×  æ`  ¦
 ? /“ ¦,  Ž & ñ Ò  o  y Œ • l   ñ  H ü @ Â

Җ Ð Æ ÒØ  ¦ ) a y n Cõ  Ä »o  l ó ø Í\  y Œ —˜ 2 ³ y n C_  ½ + Ë`  ¦ ³ ð‰ & ³ Ù ¼

–

Ð ¿ º € ª œ  s _  s  l ó ø Í — ¸× ¼– Ð y Œ —˜ 2 ³ y n C_  q ×  æ`  ¦ _

p ô  Ç .
 Qt  q ×  æ“ É r Ä »l 8 £ x õ  ITO\  • ¸  — ¸× ¼– Ð y

Œ

—˜ 2 ³ y n C_   © œ@ /& h  q ×  æ s  . ETLs  100 nm { 9  M :  H µ 1 Ï F 

g8 £ x \ " f l ó ø Í — ¸× ¼– Ð  Å # Qš ¸  H y n C_  q ×  æ s  60.7%, s 

×

 æ ü @ Җ Ð » 1 ÏØ  ¦   H y n C_  q ×  æ s  26.6%e ” `  ¦ · ú ˜ à º e ”  .

s

 Qô  Ç Ã ºu   H Fig. 2(a) \ " f ] jr   ) a l ‘ : r ½ ¨› ¸_    õ 

Fig. 4. (Color online) The far-field intensity distribu- tion emitted from the OLED as a function of the ETL thickness, which was detected in the air by using the ray tracing method. SiN layer was applied to the OLED without photonic crystals.

[29] ü < q “ §K  ^  ¦ M : l ó ø Í — ¸× ¼  H 2.4% 7 £ x \  ¦ % i t ë ß – OCE  H 2.3% y Œ ™™ è  ) a   õ s  . s  Qô  Ç   õ   H   É r 8 £ x

˜

Ð  Ï ã J] X Ò  ¦ s   8 Z  }“ É r SiN ~ à Ì} Œ •8 £ x s  Ä »o  l ó ø Í ? / F  g • ¸ ì

 r Ÿ í\  ¦  8 V , “ É r y Œ •• ¸– Ð ì  r í ß –r v €  " f s [ þ t s  ü @ Җ Ð


`

 ¦ M : e ” > y Œ •˜ Ð   8  H y Œ •• ¸– Ð { 9     H F  g‚  _  q ×  æ`  ¦ 7

£

x r (  l  M :ë  H“    כ Ü ¼– Ð K $ 3  ) a  .

2. ° Ë Ñ+ s ÇX N Ë X ì Ä “ Ó Þ OLED8 ý S ö o Ú7 _T  Ó Å + s ÇÊ Ý

OLED ½ ¨› ¸\ " f 550 nm   © œ_  y n C“ É r F  g  & ñ _  Å Òl 

 €  • 500 nm“   › ¸| \ " f Z  }“ É r F  g Æ ÒØ  ¦ ´ òÖ  ¦`  ¦ ˜ Г    כ Ü

¼– Ð ˜ Г ¦  ) a   e ”   [23]. III.A_    õ \  _  €   OCE

\

 ¦ Z  } s   H ETL _  þ j& h  ¿ ºa   H 100 nm% i  . s \    

‘

: r r Ó ý t Y Us ‚  \ " f  H Ä º‚   ETL_  ¿ ºa \  ¦ 100 nm, " é ¶: Ÿ x + þ

A F  g  & ñ Å Òl \  ¦ 500 nm – Ð “ ¦& ñ r (  `  ¦ M : þ j& h _  F  g Æ

ÒØ  ¦ ´ òÖ  ¦`  ¦
 ? /  H F  g  & ñ _  ì ø Ít 2 £ §`  ¦ ½ ¨ “ ¦  % i 



. F  g  & ñ _  Height  H Ä º‚   e ” _ – Ð 150 nm– Ð [ O & ñ % i 

Fig. 5. (Color online) The dependence of the ratio of light energy in each of the three modes as a function of the ETL thickness. SiN layer was applied to the OLED without photonic crystals.

Fig. 6. (Color online) The ratio of the light escaped from the ITO into the glass substrate as a function of (a) the radius and (b) the height of the photonic crystals. See the text for details. The ETL thickness and the period of the photonic crystals were fixed to 100 and 500 nm, respectively. The radius of the photonic crystals was fixed to be 130 nm for the case (b).



. Fig. 6(a)“ É r " é ¶: Ÿ x+ þ A F  g  & ñ _  ì ø Ít 2 £ §    o\     Ä » l

8 £ x/ITO \ " f Ä »o  l ó ø ÍÜ ¼– Ð  Å # Q“ : r y n C_  q ×  æ`  ¦ ³ ð‰ & ³ ô

 Ç . F  g  & ñ _  ì ø Ít 2 £ § \     l ó ø ͗ ¸× ¼_  q ×  æ s  ”  1 l x

Fig. 7. (Color online) The far-field intensity distribution of the light emitted from the ITO electrode as a function of the ETL thickness, which was detected in the glass substrate by using the FDTD method. The period, the radius and the height of the photonic crystals were fixed to 500, 130, and 60 nm, respectively.

  H  כ `  ¦ ^  ¦ à º e ” Ü ¼ 9 ì ø Ít 2 £ § s  130 nm { 9  M : l ó ø Í

—

¸× ¼– Ð  Å # Qš ¸  H y n C_  q ×  æ s  60.7%– Ð  © œ Z  }    H  כ

`

 ¦ · ú ˜ à º e ”  .  Ö  ¦  Q ì ø Ít 2 £ § s  130 nm“    â Ä ºü < 200 nm“    â Ä º y Œ •y Œ •\  @ /ô  Ç " é ¶  o  © œ F  g • ¸ ì  r Ÿ í• ¸ † < Êa  ³ ð r

÷ &# Q e ”  . & ñ  y Œ •+ þ AÜ ¼– Ð C u   ) a F  g  & ñ _  4» ¡ ¤  r„  

@

/g A$ í s  F  g • ¸ì  r Ÿ í\ • ¸ Õ ª@ /– Ð ì ø Í% ò ÷ &# Q e ” 6 £ §`  ¦ · ú ˜ à º e ”

 . Fig. 6(a)_    õ \     F  g  & ñ _  ì ø Ít 2 £ §`  ¦ 130 nm – Ð “ ¦& ñ r †   Ê ê F  g  & ñ _  Z  } s \  ¦    or v €  " f l ó ø Í

—

¸× ¼– Ð  Å # Qš ¸  H y n C_  q ×  æ`  ¦ Æ Ò& h  % i  . Fig. 6(b)  H Õ

ª   õ \  ¦ ˜ Ð# Œï  r  . ì ø Ít 2 £ § \  q  €   F  g  & ñ _  Z  } s 

l

ó ø ͗ ¸× ¼\  p u   H % ò † ¾ Ós   Œ •l   H t ë ß – F  g  & ñ _  Z  } s

 50 ∼ 110 nm“   › ¸| \ " f q “ §& h  Z  }“ É r à ºu \  ¦ ˜ Ðs 

“

¦ e ” 6 £ §`  ¦ · ú ˜ à º e ”  . Z  } s  60 nm“    â Ä º l ó ø ͗ ¸× ¼– Ð

 Å

# Q  H y n C_  q ×  æ s  64.5%\  s Ø Ô>  ÷ &“ ¦, F  g • ¸ ì  r Ÿ í



 H F  g  & ñ _  @ /g A$ í s  ì ø Í% ò ÷ &# Q e ” 6 £ § • ¸ S X ‰ “  ½ + É Ã º e ”  .

s

 © œ_    õ \  l ì ø ÍK  F  g  & ñ _  Å Òl \  ¦ 500 nm, ì ø Ít  2

£

§`  ¦ 130 nm, Z  } s \  ¦ 60 nm – Ð [ O & ñ ô  Ç Ê ê\  ETL_  ¿ ºa 



  o\    É r F  g Æ ÒØ  ¦ ´ òÖ  ¦`  ¦ › ¸ K  ˜ Ѐ Œ ¤ . Fig. 7“ É r ITO

Fig. 8. (Color online) The far-field intensity distribu- tion emitted from the OLED as a function of the ETL thickness, which was detected in the air by using the ray tracing method. The period, the radius and the height of the photonic crystals were fixed to 500, 130, and 60 nm, respectively.

0

A\  + þ A$ í ÷ &  H " é ¶  o  © œ_  F  g • ¸ ì  r Ÿ í\  ¦ ETL _  ¿ ºa \ 



 
  · p  כ s  . Fig. 8“ É r Fig. 7 _    õ \    H  K  F  g

‚

 Æ Ò& h  l Z O Ü ¼– Ð ½ ¨ô  Ç OLED Ä »o  l ó ø Í 0 A_  F  g • ¸ ì  r Ÿ í

\

 ¦ ETL _  ¿ ºa \    
  · p  כ s  . F  g  & ñ \  _ ô  Ç y n C _

 Æ ÒØ  ¦ õ & ñ “ É r • ¸  › ' a — ¸× ¼– Ð ”  ' Ÿ    H y n C_   à º 7 ˜'  (wave vector) \  F  g  & ñ _  Å Òl & h “   ½ ¨› ¸\  _ K  Æ Ò& h 

“

   à º 7 ˜'   8K t   H õ & ñ Ü ¼– Ð K $ 3 s  0 p x   [23, 31]. s  M : s  Æ Ò& h “    à º 7 ˜' _  ß ¼l   H 2π\  ¦ F  g  & ñ _

 Å Òl – Ð
è  H ° ú כÜ ¼– Ð   & ñ ÷ &  H X <, Fig. 2(d)\ " f ^  ¦ à º e ”

  H  כ % ƒ! 3  F  g  & ñ _  Å Òl $ í “ É r ~ ½ ӆ ¾ Ó\     B Ä º ß ¼> 

² ú

˜ t >  ÷ &Ù ¼– Ð F  g  & ñ \  _ K  s À Ò# Qt   H F  g Æ ÒØ  ¦ † ¾ Ó



© œ ´ òõ   H r  y Œ • ~ ½ ӆ ¾ Ó\  ‰ & ³$  >  _ ” > r ½ + É  כ Ü ¼– Ð \ V © œ

½

+ É Ã º e ”  . Fig. 7õ  Fig. 8“ É r & ñ  y Œ •+ þ AÜ ¼– Ð C u   ) a F  g  

&

ñ    ½ ¨› ¸_  4» ¡ ¤  r„   @ /g A$ í s  OLED_  F  g • ¸ ì  r Ÿ í\  Õ

ª@ /– Ð ì ø Í% ò ÷ &# Q e ” 6 £ §`  ¦ ˜ Ð# ŒÅ ҍ  H  כ s  . F  g  & ñ `  ¦ ¹ ¢ ¤ y

Œ

•+ þ AÜ ¼– Ð C u ô  Ç  â Ä º\   H OLED – РÒ'  % 3 # Qt   H F  g • ¸ ì

 r Ÿ í % i r  F  g  & ñ _  6» ¡ ¤  r„  @ /g A$ í `  ¦ Õ ª@ /– Ð ì ø Í% ò > 

Fig. 9. (Color online) The dependence of the ratio of light energy in each of the three modes as a function of the ETL thickness. The period, the radius and the height of the photonic crystals were fixed to 500, 130, and 60 nm, respectively.

H

†

d • ¸ S X ‰ “   % i  . Fig. 7õ  Fig. 8“ É r ¢ ¸ô  Ç ETL_  ¿ ºa    



o\    É r ç ß –[ O  › ¸| _     o (7 £ ¤ Ä »l 8 £ x ? / ) ‡6   x ÷ &  H • ¸ 

 — ¸× ¼ à º_     o)– Ð & ñ €   ~ ½ ӆ ¾ Ó F  g • ¸ [ jl  ‰ & ³$ y     1

l

x “ ¦ e ” 6 £ § • ¸ ˜ Ð# ŒÅ ғ ¦ e ”  . F  g  & ñ s  & h 6   x ) a OLED _

 OCE\  ¦ ETL _  ¿ ºa \     › ¸ ô  Ç   õ  Fig. 9\  ]

jr ÷ &# Q e ”  . ETL_  ¿ ºa  100 nm{ 9  M : SiN~ à Ì} Œ •ë ß –

&

h

6   x ) a OLED \  q K  l ó ø Í — ¸× ¼– Ð  Å # Qš ¸  H y n C_  q ×  æ s

 4.5%  8 † ¾ Ó © œ  ) a 65.2% _  à ºu \  ¦ ˜ Ðs “ ¦ e ” “ ¦, þ j7 á x& h  Ü

¼– Ð ü @ Җ Ð » 1 ÏØ  ¦ ô  Ç y n C_  q ×  æ“ É r 7.6% † ¾ Ó © œ  ) a 34.2%e ” 

`

 ¦ · ú ˜ à º e ”  .

Õ

ªX O t ë ß – Fig. 7õ  Fig. 8\  ] jr   ) a F  g • ¸ ì  r Ÿ í  H z  ´] j OLED _  µ 1 ßl  r  y Œ •\     B Ä º   y Œ ™ >   † 1   כ s 



  H & h `  ¦ ˜ Ð# ŒÅ ғ ¦ e ”  . s  Qô  Ç r  y Œ • : £ ¤$ í s  OLED _

 ™ è  $ í 0 p x \  a % ~ t  · ú §“ É r % ò † ¾ Ó`  ¦ p u o    H & h “ É r  

"

î  . s \  ¦ ¢ - a  or ~  ´ à º e ”   H ~ ½ ÓZ O  ×  æ 
  H Ä »o  l  ó

ø Í 5 Å q \  í ß –ê ø Í8 £ x`  ¦ + þ A$ í K " f y n C_  Á º Œ •0 A& h “   ~ ½ ӆ ¾ Ó „  ¨ 8 Š

`

 ¦ Ä »• ¸   H  כ s  . ì ø Ít 2 £ § s  500 nm“   p  í ß –ê ø Í (Mie scattering) { 9  \  ¦ 10

∼ 10

mm

_  x 9 • ¸ # 3 0 A ? /\ 

"

f Ä »o  l ó ø Í\  Ÿ í† < Êr †    â Ä º_  y Œ • › ¸| Z >  F  g • ¸ ì  r Ÿ í

Fig. 10 \  ] jr ÷ &# Q e ”  . { 9  _  x 9 • ¸ & | 9 à º2 Ÿ ¤ F  g  

&

ñ _  @ /g A$ í \  _ K  + þ A$ í ÷ &  H r  y Œ • : £ ¤$ í s  & h & h  ¢ - a  o

÷ &€  " f | à Ð! Qr î ß – ì  r Ÿ í\    H] X  >  H † d`  ¦ · ú ˜ à º e ”  . s  Q ô

 Ç   õ   H í ß –ê ø Í { 9  `  ¦  Ö ¸6   x † < ÊÜ ¼– Ð+ ‹ F  g  & ñ & h 6   x \   

 É

r r  y Œ •Z >  6 f• ¸ x 9  Ò  o• ¸    o\  ¦ ] j# Q½ + É Ã º e ”    H  כ

`

 ¦ _ p ô  Ç . Fig. 11“ É r p  í ß –ê ø Í{ 9  _  ì ø Ít 2 £ § x 9  x 9 • ¸_ 

†

< Êà º– Ð › ¸ ô  Ç OLED_  OCEs  . F  g  & ñ ë ß – & h 6   x ½ + É  â Ä

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  H F  g  & ñ \  _ ô  Ç • ¸  › ' a — ¸× ¼_  Æ ÒØ  ¦ \  í ß –ê ø Í{ 9  \ 

Fig. 10. (Color online) The far-field intensity distribution emitted from the photonic crystal-applied OLED as a function of the density of Mie scattering particles with a radius of 500 nm included in the glass substrate. The period, the radius and the height of the photonic crystals were fixed to 500, 130, and 60 nm, respectively.

Fig. 11. (Color online) The outcoupling efficiency of the photonic crystal-applied OLED as a function of the den- sity and the radius of Mie scattering particles included in the glass substrate. The period, the radius and the height of the photonic crystals were fixed to 500, 130, and 60 nm, respectively.

_

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s

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% 3  .

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