TY - JOUR
T1 - The influence of tetrakis-ethylhexyloxy groups substituted in PPV derivative for PLEDs
AU - Jin, Youngeup
AU - Kim, Jin Young
AU - Song, Suhee
AU - Xia, Yangjun
AU - Kim, Jaehong
AU - Woo, Han Young
AU - Lee, Kwanghee
AU - Suh, Hongsuk
N1 - Funding Information:
This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (R01-2007-000-20853-0).
PY - 2008/1/21
Y1 - 2008/1/21
N2 - New electroluminescent polymer with tetrakis-alkoxy group, poly[2,3,5,6-tetrakis(2-ethylhexyloxy)-1,4-phenylenevinylene] (TEH-PPV), has been synthesized by the Gilch polymerization. In solid film state, the TEH-PPV exhibits absorption spectra with maximum peaks at 451 nm, and PL spectrum at 505-545 nm. As compared to MEH-PPV, TEH-PPV with tetrakis-ethylhexyloxy groups in phenylene unit can get shorter conjugation length, and had more blue shifted absorption and emission peaks due to steric hindrance, in spite of increasing the number of alkoxy substituents which may increase the effective conjugation length caused by the electron-donating effect. The polymer LEDs (ITO/PEDOT/polymer/Al) of TEH-PPV showed emission with maximum peaks at around 505-590 nm. Tetrakis-ethylhexyloxy groups induced very typical vibronically structured band in solid film state, since the conjugated backbone is twisted by steric hindrance. And they can enhance the internal efficiency of the conjugated polymer as emissive layer in PLED because of the restraint of inter-chain interaction by the avoidance of close packing to give decent device performance.
AB - New electroluminescent polymer with tetrakis-alkoxy group, poly[2,3,5,6-tetrakis(2-ethylhexyloxy)-1,4-phenylenevinylene] (TEH-PPV), has been synthesized by the Gilch polymerization. In solid film state, the TEH-PPV exhibits absorption spectra with maximum peaks at 451 nm, and PL spectrum at 505-545 nm. As compared to MEH-PPV, TEH-PPV with tetrakis-ethylhexyloxy groups in phenylene unit can get shorter conjugation length, and had more blue shifted absorption and emission peaks due to steric hindrance, in spite of increasing the number of alkoxy substituents which may increase the effective conjugation length caused by the electron-donating effect. The polymer LEDs (ITO/PEDOT/polymer/Al) of TEH-PPV showed emission with maximum peaks at around 505-590 nm. Tetrakis-ethylhexyloxy groups induced very typical vibronically structured band in solid film state, since the conjugated backbone is twisted by steric hindrance. And they can enhance the internal efficiency of the conjugated polymer as emissive layer in PLED because of the restraint of inter-chain interaction by the avoidance of close packing to give decent device performance.
KW - PPV
KW - Polymer light-emitting diodes
KW - Tetrakis-alkoxy group
UR - http://www.scopus.com/inward/record.url?scp=38349074074&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2007.11.040
DO - 10.1016/j.polymer.2007.11.040
M3 - Article
AN - SCOPUS:38349074074
SN - 0032-3861
VL - 49
SP - 467
EP - 473
JO - Polymer
JF - Polymer
IS - 2
ER -