TY - JOUR
T1 - Interface control by surface-initiated deposition polymerization and its application to organic light-emitting devices
AU - Kawakami, Akira
AU - Katsuki, Kiyoi
AU - Advincula, Rigoberto C.
AU - Tanaka, Kuniaki
AU - Ogino, Kenji
AU - Usui, Hiroaki
PY - 2008/4/25
Y1 - 2008/4/25
N2 - Surface-initiated deposition polymerization was applied to the preparation of a hole transport layer (HTL) on an indium-tin oxide (ITO) electrode. A silane-based self-assembled monolayer (SAM) that has an azo terminal group was prepared on an ITO surface on which a vinyl monomer of carbazole (CPA) or tetraphenyldiaminobiphenyl (vTPD) was deposited by physical vapor deposition. The polymerization of the HTL was achieved by electron-assisted deposition. UV irradiation, as well as conventional evaporation, was not capable of growing polymer films on the SAM. Organic light-emitting diodes (OLEDs) were prepared by depositing tris(8-quinolinolato) aluminum (Alq3) on the HTL. The surface-initiated deposition polymerization was effective in markedly increasing device current flow and reducing turn-on voltage. However, luminescence efficiency was not improved by this method owing to improper carrier balance under excessive hole injection. Nevertheless, surface-initiated deposition polymerization was effective in improving film morphology, stability, and hole injection characteristics.
AB - Surface-initiated deposition polymerization was applied to the preparation of a hole transport layer (HTL) on an indium-tin oxide (ITO) electrode. A silane-based self-assembled monolayer (SAM) that has an azo terminal group was prepared on an ITO surface on which a vinyl monomer of carbazole (CPA) or tetraphenyldiaminobiphenyl (vTPD) was deposited by physical vapor deposition. The polymerization of the HTL was achieved by electron-assisted deposition. UV irradiation, as well as conventional evaporation, was not capable of growing polymer films on the SAM. Organic light-emitting diodes (OLEDs) were prepared by depositing tris(8-quinolinolato) aluminum (Alq3) on the HTL. The surface-initiated deposition polymerization was effective in markedly increasing device current flow and reducing turn-on voltage. However, luminescence efficiency was not improved by this method owing to improper carrier balance under excessive hole injection. Nevertheless, surface-initiated deposition polymerization was effective in improving film morphology, stability, and hole injection characteristics.
KW - Deposition polymerization
KW - OLED
KW - Organic EL
KW - Organic light-emitting diode
KW - SAM
KW - Self-assembled monolayer
KW - Surface-initiated polymerization
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U2 - 10.1143/JJAP.47.3156
DO - 10.1143/JJAP.47.3156
M3 - Article
AN - SCOPUS:50249093030
SN - 0021-4922
VL - 47
SP - 3156
EP - 3161
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - 4 PART 2
ER -