Browsing by Author "Hu, YH"

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Highly efficient red phosphorescent osmium(II) complexes for OLED applications
(2004-07-19)
Tung, YL
;
Wu, PC
;
Liu, CS
;
Chi, Y
;
Yu, JK
The nonionic, red-emitting complexes [Os(fppz)(2)L-2] (L = PPh2Me (1), PPhMe2 (2)) and [Os(bptz)(2)L-2] (L = PPh2Me (3)) were synthesized, showing highly intense red phosphorescent emission in CH2Cl2 solution at lambda(max) 617, 632, and 649 nm, respectively. The electroluminescent properties of these compounds on OLEDs showed promising device efficiencies required for future OLED applications.
Type-II CdSe/CdTe/ZnTe (core-shell-shell) quantum dots with cascade band edges: The separation of electron (at CdSe) and hole (at ZnTe) by the CdTe layer
(2005-12-01)
Chen, CY
;
Cheng, CT
;
Lai, CW
;
Hu, YH
;
Chou, PT
The rational design and synthesis of CdSe/CdTe/ZnTe (core-shell-shell) type-II quantum dots are reported. Their photophysical properties are investigated via the interband CdSe -> ZnTe emission and its associated relaxation dynamics. In comparison to the strong CdSe (core only) emission (lambda(max) approximate to 550 nm, Phi(f) approximate to 0.28), a moderate CdSe -> Cd Te emission (lambda(max) approximate to 1026 nm, Phi(f) approximate to 1.2 x 10(-3)) and rather weak CdSe -> Zn Te interband emission (lambda(max) approximate to 1415 nm, Phi(f) approximate to 1.1 x 10(-5)) are resolved for the CdSe/CdTe/ ZnTe structure (3.4/1.8/1.3 nm). Capping CdSe/CdTe with ZnTe results in a distant electron-hole separation between CdSe (electron) and ZnTe (hole) via an intermediate CdTe layer In the case of the CdSe/CdTe/ ZnTe structure, a lifetime as long as 150 ns is observed for the CdSe -> Zn Te (1415 nm) emission. This result further indicates an enormously long radiative lifetime of approximate to 10 ms. Upon excitation of the CdSe/CdTe/ Zn Te structure, the long-lived charge separation may further serve as an excellent hole carrier for catalyzing the redox oxidation reaction.