论文信息 - Characteristics of optical response in red organic light-emitting diodes using two dopant system for application to the optical link devices

Characteristics of optical response in red organic light-emitting diodes using two dopant system for application to the optical link devices

Abstract We investigated the transient electroluminescence (EL) and modulation characteristics of red organic light-emitting diodes (OLEDs) consisting of 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTI) and 5,6,11,12-tetraphenylnaphthacene (rubrene) doped into tris(8-hydroxyquinoline)aluminum (Alq3). The transient EL waveforms showed two components, an initial overshooting peak followed by a constant component, indicating that the excess amount of accumulated charges simultaneously recombine at the moment of onset. This overshoot effect reduced the rise time of transient EL and enhanced the optical output of the OLEDs, and hence the cutoff frequency was increased when the pulse voltage was applied to the device. We demonstrated that the red OLEDs are suitable for use in high-speed switching applications driven at more than 100 MHz, and in electro-optical conversion devices for transmitting video signals.

[1] Y. Hamada,et al. Red organic light-emitting diodes using an emitting assist dopant , 1999 .

[2] John K. Borchardt,et al. Developments in organic displays , 2004 .

[3] Hal-Bon Gu,et al. Exciplex emission and energy transfer in white light-emitting organic electroluminescent device , 2003 .

[4] Shizuo Tokito,et al. Energy-transfer and light-emission mechanism of blue phosphorescent molecules in guest-host systems , 2004 .

[5] Shui-Tong Lee,et al. Transient electroluminescence of organic quantum-well light-emitting diodes , 2002 .

[6] Saburo Imamura,et al. Organic electroluminescent diodes as a light source for polymeric waveguides — toward organic integrated optical devices , 2001 .

[7] C. Tang,et al. Organic Electroluminescent Diodes , 1987 .

[8] Hirotake Kajii,et al. Blue organic light-emitting diode as the electro-optical conversion device for high-speed switching applications , 2002 .

[9] Stephen R. Forrest,et al. High-efficiency organic electrophosphorescent devices with tris(2-phenylpyridine)iridium doped into electron-transporting materials , 2000 .