Browsing by Author "Chang, Sheng-Yuan"

Now showing 1 - 4 of 4

A solution-processable bipolar molecular glass as a host material for white electrophosphorescent devices
(2008)
Chien, Chen-Han
;
Kung, Liang-Rern
;
Wu, Chen-Hao
;
Shu, Ching-Fong
;
Chang, Sheng-Yuan
A solution-processable bipolar material tBu-OXDTFA comprising an electron-rich triphenylamine core and electron-deficient oxadiazole/ fluorene peripheries was synthesized. This dendrimer-like molecule not only possesses a high triplet energy (2.74 eV) but also exhibits excellent film-forming properties upon solution processing. We achieved highly efficient white electrophosphorescent OLEDs (22.3 cd A(-1), 11.6%) through solution processing, wherein the single white emitting layer was readily formed after spin-coating a solution of blue- and red-phosphor co-dopants containing tBu-OXDTFA as the host matrix.
Electrophosphorescent polyfluorenes containing osmium complexes in the conjugated backbone
(2008-05-09)
Chien, Chen-Han
;
Liao, Song-Fu
;
Wu, Chen-Hao
;
Shu, Ching-Fong
;
Chang, Sheng-Yuan
Electrophosphorescent copolymers have been synthesized by covalent bonding of a red-emitting osmium complex Os(bpftz), which contains two 3-trifluoromethyl-5-(4-tert-butyl-2-pyridyl)triazolate (bpftz) cyclometalated ligands, into the backbone of a bipolar polyfluorene (PF) copolymer. Employing these copolymers, a highly efficient red polymer light-emitting diode has been realised that has an external quantum efficiency of 18.0%, a maximum brightness of 38000 cd m(-2), and an emission centered at 618 nm. In addition, after incorporating appropriate amounts of green-emitting benzothiadiazole (BT) and the aforementioned Os(bpftz) into the bipolar PF, an efficient white-light electroluminescent polymer is obtained that displays simultaneous blue, green, and red emissions.
Pt(II) Complexes with 6-(5-Trifluoromethyl-Pyrazol-3-yl)-2,2 '-Bipyridine Terdentate Chelating Ligands: Synthesis, Characterization, and Luminescent Properties
(2008-01-01)
Chen, Jing-Lin
;
Chang, Sheng-Yuan
;
Chi, Yun
;
Chen, Kellen
;
Cheng, Yi-Ming
A series of Pt(II) complexes Pt(fpbpy)Cl (1), Pt(fpbpy)(OAc) (2), Pt(fpbpy)(NHCOMe) (3), Pt(fpbpy)(NHCOEt) (4), and [Pt(fpbpy)(NCMe)](BF(4)) (5) with deprotonated 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine terdentate ligand are prepared, among which 1 is converted to complexes 2-5 by a simple ligand substitution. Alternatively, acetamide complex 3 is prepared by hydrolysis of acetonitrile complex 5, while the back conversion from 3 to 1 is regulated by the addition of HCl solution, showing the reaction sequence 1 -> 5 -> 3 -> 1. Mullilayer OLED devices are successfully fabricated by using triphenyl-(4-(9-phenyl-9H-fluoren-9-yl)phenyl) silane (TPSi-F) as host material and with doping concentrations of 1 varying from 7 to 100%. The electroluminescence showed a substantial red-shifting versus the normal photoluminescence detected in solution. Moreover, at a doping concentration of 28%, the device showed a saturated red luminescence with a maximum external quantum yield of 8.5% at 20 mA cm(-2) and a peak luminescence of 47543 cd m(-2) at 18.5 V.
Pt-II Complexes with 6-(5-Trifluoromethyl-Pyrazol-3-yl)-2,2 '-Bipyridine Terdentate Chelating Ligands: Synthesis, Characterization, and Luminescent Properties
(2008-01-01)
Chen, Jing-Lin
;
Chang, Sheng-Yuan
;
Chi, Yun
;
Chen, Kellen
;
Cheng, Yi-Ming
A series of Pt-II complexes Pt(fpbpy)Cl (1), Pt(fpbpy)(OAc) (2), Pt(fpbpy)(NHCOMe) (3), Pt(fpbpy)(NHCOEt) (4), and [Pt(fpbpy)(NCMe)](BF4) (5) with deprotonated 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine terdentate ligand are prepared, among which 1 is converted to complexes 2-5 by a simple ligand substitution. Alternatively, acetamide complex 3 is prepared by hydrolysis of acetonitrile complex 5, while the back conversion from 3 to 1 is regulated by the addition of HCl solution, showing the reaction sequence 1 -> 5 -> 3 -> 1. Mullilayer OLED devices are successfully fabricated by using triphenyl-(4-(9-phenyl-9H-fluoren-9-yl)phenyl) silane (TPSi-F) as host material and with doping concentrations of 1 varying from 7 to 100%. The electroluminescence showed a substantial red-shifting versus the normal photoluminescence detected in solution. Moreover, at a doping concentration of 28%, the device showed a saturated red luminescence with a maximum external quantum yield of 8.5% at 20 mA cm(-2) and a peak luminescence of 47543 cd m(-2) at 18.5 V.