Search | Korea Science

Jang, Han-Na;Lee, Ju-Yeon
- Bulletin of the Korean Chemical Society
- /
- v.29 no.5
- /
- pp.933-938
- /
- 2008
2,4-Di-(2'-hydroxyethoxy)benzylidenemalononitrile (3) was prepared and polymerized with terephthaloyl chloride and adipoyl chloride to yield novel Y-type polyesters 4 and 5 containing dioxybenzylidenemalononitrile groups as NLO-chromophores, which constituted parts of the polymer backbone. The resulting polymers 4 and 5 are soluble in common organic solvents such as acetone and N,N-dimethylformamide. Polymers 4 and 5 showed thermal stability up to 300 ${^{\circ}C}$ in thermogravimetric analysis with glass-transition temperatures obtained from differential scanning calorimetry in the range 83-94 ${^{\circ}C}$. The second harmonic generation (SHG) coefficients ($d_{33}$) of poled polymer films at the 1064 nm fundamental wavelength were around $6.48\;{\times}\;10^{-9}$ esu. The dipole alignment exhibited high thermal stability even at 10 ${^{\circ}C}$ higher than $T_g$ and no significant SHG decay was observed below 105 ${^{\circ}C}$ partially due to the main-chain character of polymer structure, which is acceptable for NLO device applications.
https://doi.org/10.5012/bkcs.2008.29.5.933 인용 PDF KSCI

Helander, M.G.;Wang, Z.B.;Lu, Z.H.
- 한국정보디스플레이학회:학술대회논문집
- /
- 2009.10a
- /
- pp.112-114
- /
- 2009
Charge injection at electrode-organic interfaces is key to the performance, lifetime and stability of organic electronic devices. The link between fundamental material properties and the energy-level alignment at electrode-organic interfaces will be discussed. In addition the impact of the injection barrier height-a parameterization of the energylevel alignment-on device characteristics will also be discussed.
PDF

Cho, You-Jin;Kim, Mi-Sung;Lee, Ju-Yeon
- Bulletin of the Korean Chemical Society
- /
- v.32 no.2
- /
- pp.424-430
- /
- 2011
A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to $270^{\circ}C$ from TGA thermogram with $T_g$ value obtained from DSC thermogram near $155^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer film at 1560 nm fundamental wavelength is $3.56{\times}10^{-9}$ esu. Polymer 7 exhibits a thermal stability even at $5^{\circ}C$ higher than $T_g$, and no significant SHG decay is observed below $160^{\circ}C$, which is acceptable for nonlinear optical device applications.
https://doi.org/10.5012/bkcs.2011.32.2.424 인용 PDF KSCI

Kim Beom-Kyung;Kim Do-Hoi;Chung Jae-Sun;Kim Young-Ju;Seo In-Seon;Kwon Soon-Ki;Song Ki-Gook
- Polymer(Korea)
- /
- v.30 no.4
- /
- pp.362-366
- /
- 2006
It was found by polarized FTIR spectroscopic studies that pentacene molecules are arranged with their molecular axes perpendicular to the substrate surface when pentacene films are deposited on a polyimide alignment layer. The ring plane in a pentacene molecule is arranged parallel to the rubbing direction of the polyimide alignment film while no specific arrangement of vertically deposited pentacene molecules was found for the film without rubbing. The pentacene band at $1296cm^{-1}$ which has a transition dipole moment parallel to the ring plane is much stronger in a polarized IR spectrum of parallel to the rubbing direction, whereas the band at $908cm^{-1}$ whose transition dipole align normal to the ring plane shows much stronger intensity in a spectrum of perpendicular to the rubbing direction. These findings indicate that orientation of polyimide chains affects the arrangement of pentacene molecules when they are deposited on a polyimide alignment film.
PDF KSCI