The Experts below are selected from a list of 23061 Experts worldwide ranked by ideXlab platform
Kyoung Soo Yook - One of the best experts on this subject based on the ideXlab platform.
-
Low Driving Voltage in white organic light-emitting diodes using an interfacial energy barrier free multilayer emitting structure
Journal of Luminescence, 2009Co-Authors: Kyoung Soo Yook, Soon Ok Jeon, Chul Woong Joo, Jun Yeob LeeAbstract:Abstract The Driving Voltage of white organic light-emitting diodes (WOLEDs) with blue fluorescent and red phosphorescent emitting materials was lowered by using a device architecture with little energy barrier between emitting layers. A mixed layer of hole and electron transport materials was used as a host material and an interlayer, reducing the Driving Voltage of WOLEDs. The Driving Voltage of WOLEDs was reduced by more than 4 V and power efficiency of WOLEDs was improved by more than 40% due to little energy barrier for holes and electrons injection in light-emitting layer. In addition, there was little change of electroluminescence spectra from 100 to 10,000 cd/m 2 .
-
low Driving Voltage in organic light emitting diodes using moo3 as an interlayer in hole transport layer
Synthetic Metals, 2009Co-Authors: Kyoung Soo YookAbstract:Abstract Driving Voltage of organic light-emitting diodes (OLEDs) was lowered by applying MoO3 as an interlayer between hole injection layer (HIL) and hole transport layer (HTL). MoO3 was effective as an interlayer between HIL and HTL due to its valence band of around 5.3 eV which is suitable for hole injection. Hole injection from HIL to HTL was enhanced by MoO3 interlayer and Driving Voltage of green fluorescent device could be lowered by 1.3 V at 1000 cd/m2 by using thin MoO3 interlayer.
-
organic light emitting bistable memory device with high on off ratio and low Driving Voltage
Applied Physics Letters, 2008Co-Authors: Kyoung Soo Yook, Jyongsik JangAbstract:Organic light emitting bistable memory devices (OLEBDs) with a dual function of organic light emitting diodes and organic memory devices were developed by using 0.5 nm thick MoO3 as an interlayer between hole injection layer and hole transport layer. The hole transport unit with MoO3 interlayer played a role of a memory unit as well as a hole transport unit. High on/off ratio over 1000 was obtained at a reading Voltage of 1 V and Driving Voltage was lowered by MoO3. In addition, two different luminances were obtained at the same Driving Voltage by changing writing Voltage of OLEBDs.
Hany Aziz - One of the best experts on this subject based on the ideXlab platform.
-
low Driving Voltage simplified tandem organic light emitting devices by using exciplex forming hosts
Applied Physics Letters, 2014Co-Authors: Dongying Zhou, Yingjie Zhang, Liangsheng Liao, Hany AzizAbstract:Tandem organic light-emitting devices (OLEDs), i.e., OLEDs containing multiple electroluminescence (EL) units that are vertically stacked, are attracting significant interest because of their ability to realize high current efficiency and long operational lifetime. However, stacking multiple EL units in tandem OLEDs increases Driving Voltage and complicates fabrication process relative to their standard single unit counterparts. In this paper, we demonstrate low Driving Voltage tandem OLEDs via utilizing exciplex-forming hosts in the EL units instead of conventional host materials. The use of exciplex-forming hosts reduces the charge injection barriers and the trapping of charges on guest molecules, resulting in the lower Driving Voltage. The use of exciplex-forming hosts also allows using fewer layers, hence simpler EL configuration which is beneficial for reducing the fabrication complexity of tandem OLEDs.
-
Causes of Driving Voltage rise in phosphorescent organic light emitting devices during prolonged electrical Driving
Applied Physics Letters, 2012Co-Authors: Hossein Zamani Siboni, Hany AzizAbstract:We studied the Driving Voltage stability of typical phosphorescent organic light emitting devices (PHOLEDs) based on 4,4′-bis(carbazol-9-yl)biphenyl and Tris(2-phenylpyridine)iridium(III) host:guest system. The results show that the gradual increase in Voltage often observed with prolonged electrical Driving is mainly governed by the accumulation of holes at the emission layer/hole blocking layer interface. Reducing the build-up of hole space charges in this region, for example, by means of eliminating guest molecules from the vicinity of the interface, leads to a significant improvement in the stability of PHOLED Driving Voltage.
Dongying Zhou - One of the best experts on this subject based on the ideXlab platform.
-
low Driving Voltage simplified tandem organic light emitting devices by using exciplex forming hosts
Applied Physics Letters, 2014Co-Authors: Dongying Zhou, Yingjie Zhang, Liangsheng Liao, Hany AzizAbstract:Tandem organic light-emitting devices (OLEDs), i.e., OLEDs containing multiple electroluminescence (EL) units that are vertically stacked, are attracting significant interest because of their ability to realize high current efficiency and long operational lifetime. However, stacking multiple EL units in tandem OLEDs increases Driving Voltage and complicates fabrication process relative to their standard single unit counterparts. In this paper, we demonstrate low Driving Voltage tandem OLEDs via utilizing exciplex-forming hosts in the EL units instead of conventional host materials. The use of exciplex-forming hosts reduces the charge injection barriers and the trapping of charges on guest molecules, resulting in the lower Driving Voltage. The use of exciplex-forming hosts also allows using fewer layers, hence simpler EL configuration which is beneficial for reducing the fabrication complexity of tandem OLEDs.
D A B Miller - One of the best experts on this subject based on the ideXlab platform.
-
wideband low Driving Voltage traveling wave mach zehnder modulator for rf photonics
IEEE Photonics Technology Letters, 2008Co-Authors: Mona Jarrahi, D A B MillerAbstract:We report the design, fabrication, and testing of a traveling-wave Mach-Zehnder modulator on a GaAs substrate. Operating at 870-nm wavelength, we obtained an extremely low Driving Voltage of 0.45 V and a high measurement-instrument-limited small-signal modulation bandwidth of 18 GHz, projected to an estimated bandwidth of 50 GHz. We have also monolithically integrated photodetectors with an impulse response of 8-ps full-width at half-maximum, and a saturation power of 330 mW, giving a flexible high-performance platform for RF photonics.
Jun Yeob Lee - One of the best experts on this subject based on the ideXlab platform.
-
Low Driving Voltage in white organic light-emitting diodes using an interfacial energy barrier free multilayer emitting structure
Journal of Luminescence, 2009Co-Authors: Kyoung Soo Yook, Soon Ok Jeon, Chul Woong Joo, Jun Yeob LeeAbstract:Abstract The Driving Voltage of white organic light-emitting diodes (WOLEDs) with blue fluorescent and red phosphorescent emitting materials was lowered by using a device architecture with little energy barrier between emitting layers. A mixed layer of hole and electron transport materials was used as a host material and an interlayer, reducing the Driving Voltage of WOLEDs. The Driving Voltage of WOLEDs was reduced by more than 4 V and power efficiency of WOLEDs was improved by more than 40% due to little energy barrier for holes and electrons injection in light-emitting layer. In addition, there was little change of electroluminescence spectra from 100 to 10,000 cd/m 2 .
