Polyaniline-based conducting polymer compositions with a high work function for hole-injection layers in organic light-emitting diodes: formation of ohmic contacts.
It is a great challenge to develop solution-processed, polymeric hole-injection layers (HILs) that perform better than small molecular layers for realizing high-performance small-molecule organic light-emitting diodes (SM-OLEDs). We have greatly improved the injection efficiency and the current efficiency of SM-OLEDs by introducing conducting polymer compositions composed of polyaniline doped with polystyrene sulfonate and perfluorinated ionomer (PFI) as the HIL. During single spin-coating of conducting polymer compositions, the PFI layer was self-organized at the surface and greatly increased the film work function. It enhanced hole-injection efficiency and current efficiency by introducing a nearly ohmic contact and improving electron blocking. Our results demonstrate that solution-processed polyaniline HILs with tunable work functions are good candidates for reducing process costs and improving OLED performance.
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Mi-Ri
MR
Choi
Seong-Hoon
SH
Woo
Tae-Hee
TH
Han
Kyung-Geun
KG
Lim
Sung-Yong
SY
Min
Won Min
WM
Yun
Oh Kwan
OK
Kwon
Chan Eon
CE
Park
Kwan-Do
KD
Kim
Hoon-Kyu
HK
Shin
Myeong-Suk
MS
Kim
Taeyong
T
Noh
Jong Hyeok
JH
Park
Kyoung-Hwan
KH
Shin
Jyongsik
J
Jang
Tae-Woo
TW
Lee
D000814:Aniline Compounds; D004553:Electric Conductivity; D055664:Electrochemical Techniques; D004583:Electrons; D008027:Light; D011108:Polymers; D011137:Polystyrenes; D012996:Solutions
D000814:Aniline Compounds; D011108:Polymers; D011137:Polystyrenes; D012996:Solutions; C416807:polyaniline; C003321:polystyrene sulfonic acid