http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Jun Ying,Jinhua Han,Lanyi Xiang,Wei Wang,Wenfa Xie 한국물리학회 2015 Current Applied Physics Vol.15 No.7
In this work, we study charge trapping in floating-gate organic thin-film transistor nonvolatile memories (FG-OTFT-NVMs) fabricated by a simple method. The inner discrete distribution aluminum nanoparticles (Al-Nps) and the continuous compact thin alumina film were formed to act as the floating-gate and the tunneling dielectric layer, respectively by thermally evaporated Al at a slow rate and then heat annealed in dry air. The devices exhibited remarkable photoresponse and memory effect. Compared with the unidirectional threshold voltage (VT) shifts of memories by programming/erasing (P/E) in dark, larger bidirectional VT shifts were obtained by light-assisted programming, and therefore the memory performances were enhanced. A multilevel memory behavior was observed in our memories, which depended on programming conditions. The charge trapping mechanisms of memories operated in dark and under illumination are discussed, respectively. The results indicate that optimal memory performance requires charge carriers of both polarities, because it is a very efficient method to enlarge the memory window and to lower the P/E voltage by overwriting trapped charges by injected charges of opposite polarity.
Kai Xu,Yang Li,Wei Zhang,Letian Zhang,Wenfa Xie 한국물리학회 2014 Current Applied Physics Vol.14 No.1
Gold nanoparticles (GNPs) on the performance of the phosphorescent organic light-emitting devices (OLEDs) were investigated. The green phosphorescent OLEDs with GNPs incorporated in hole transporting layer (HTL) or hole blocking layer (HBL) were fabricated using thermal evaporation technique. The results indicated that the performance of the OLEDs with GNPs were dependent on the position of the GNPs. The optimized device with GNPs in HBL shows enhanced current efficiency and reduced efficiency roll-off. However, the efficiency of the device with GNPs in HTL was decreased. The detailed physical mechanism is investigated in order to unveil such difference.
Angle-stable top-emitting white organic light-emitting devices employing a down-conversion layer
Shihao Liu,Xuemei Wen,Wenbo Liu,Wei Zhang,Jing-Yuan Wang,Wenfa Xie,Letian Zhang 한국물리학회 2014 Current Applied Physics Vol.14 No.11
Angle-stable white top-emitting organic light-emitting devices (WTEOLEDs) by the combination of a blue TEOLED with a down-conversion (DC) layer are demonstrated. The DC layer is composed of red fluorescent dye doped in a host of tris (8-hydroxy-quinolinato) aluminum. The TEWOLED shows a CIE coordinates of (0.240, 0.332) and a maximum current efficiency of 3.95 cd/A. Furthermore, theWTEOLED shows excellently angle-stable characteristic, the CIE coordinates at 20 mA/cm2 only shift by (0.023, 0.007) from 0 to 60. It can be attributed to the angle-stable blue TEOLED based on the Ag/Ge/Ag transparent cathode.
Tianyu Zhang,Tong Li,Wei Hu,Weiqi Wang,Letian Zhang,Wenfa Xie 한국물리학회 2014 Current Applied Physics Vol.14 No.5
White organic light-emitting devices (WOLEDs) with fluorescent donor-acceptor-substituted spirobifluorene compounds (red 2-diphenylamino-7-(2,2-dicyanovinyl)-9,90-spirobifluorene and blue 2- diphenylamino-7-(2,2-diphenylvinyl)-9,90-spirobifluorene) have been fabricated. The optimized WOLEDs shows a maximum current efficiency 5.9 cd/A and very low efficiency roll-off. From the brightness at maximum current efficiency to high brightness of 10000 cd/m2, the current efficiency rolloff is only 0.4%. It can be attributed to the ambipolar blue fluorescent emitter with voltage-independnet mobility which makes the device having a broader charge recombination zone and balance of carrier transport.
High efficiency top-emitting white organic light-emitting devices with a (metal/organic)_2 cathode
Wenyu Ji,Letian Zhang,Mo Liu,Jing Wang,Guoqiang Liu,Wenfa Xie,Hanzhuang Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.6
White top-emitting organic light-emitting devices (TEOLEDs) were fabricated on a glass substrate with metal/organic multilayer of (Ag/Alq_3)_2 (Alq3 is tris-(8-hydroxyquinoline) aluminum) as cathode. White TEOLEDs with high efficiencywere obtained due to the microcavity effects.Andthe (Ag/Alq_3)_2 cathode,which adjusted the optical characteristics of the devices, played an important role. In addition, Alq_3―Ag―Alq_3multilayer could work as a buffer layer, which would simplify the process of encapsulation for devices.We also calculated the electroluminescence spectrum of devices encapsulated with Al_2O_3 (150 nm) and Al_2O_3(75 nm)/ZrO_2(75 nm). And the results indicated that the CIE coordinates is almost the same between with and without encapsulating.