| Summary: | 碩士 === 正修科技大學 === 化工與材料工程研究所 === 97 === Two series of light emitting single polymers (PFS series and PFTS
series) are prepared by incorporating different contents of monomers into
the main chain of polyfluorene. PFS series contain different contents of
2,2':5',2'-terthiophene moieties; PFTS series comprise 5 mol%
2,3,4,5-tetraphenyl thiophene (TP) and different amount of 2,2':5',2'
-terthiophene moieties. The monomers and polymers have been
characterized by mass, elemental analysis, 1H-NMR, 13C-NMR, UV/vis,
GPC, thermogravimetric analysis, and fluorescence spectroscopy. The
thermal properties of polymer were investigated by TGA. The
decomposition temperatures (Td) of PFS series and PFTS series range from
319 to 402°C and 404 to 422°C, respectively. All differential scanning
calorimetry (DSC) scans for the two series of polymers do not show any
glass transition in the temperature range up to 300 °C.
The optical properties of these polymers are studied by UV/vis and PL
spectroscopic methods. The polymers of PFS series and PFTS series
exhibit the maximum absorption in the range of 373~382 nm and
374~381nm in liquid solution, respectively. The range of 367~378 nm and
376~379 nm in thin film demonstrate the maximum absorption for both,
respectively. The polymers of PFS series and PFTS series exhibit the
maximum emission in the range of 411~414 nm and 413~415 nm in liquid
solution, respectively. The range of 503~592 nm and 502~543 nm in thin
film demonstrate the maximum absorption for both, respectively.
Single layer devices (ITO/PEDOT:PSS/polymer/LiF/Al) are
fabricated with these polymers. The color coordinates (0.32, 0.35) of
PFTS-3 devices in the best condition for the turn-on voltage of 4.5V and
the highest brightness of 558 cd/m2 could meet pure white light (0.33, 0.33)
of the ideal CIE chromaticity coordinates. We can find the feed ratio of the
white light emitting single polymers is 92 mol% fluorine moieties, 5 mol%
TP moieties and 3 mol% 2,2':5',2'-terthiophene moieties. According to
cyclic voltametry (CV), HOMO level of PFS series and PFTS series could
reveal in the range of -5.61~ -5.73 eV and -5.69~ -5.73 eV, respectively.
The range of -2.69~ -2.79 eV and -2.74~ -2.76 eV could indicate LUMO
level of them, respectively.
|
|---|
