• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.422-423
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• 2007

In this work, Organic Light Emitting Diodes using LiF as a electron-injecting interfacial have been fabricated for efficiency enhancements. This interfacial layer is interposed between Al/$Alq_3$ layer. The brightness and specific character as current density are higher than those of the device without it. To find best thickness of LiF layer, we used some samples with various thickness. The LiF interposition at the Al/$Alq_3$ interface encouraged the electrons injection and balances the injection numbers of hole and electron in the emission layer.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.3
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• pp.190-197
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• 2011

This paper presents a 144 GHz divide-by-2 injection locked frequency divider (ILFD) with inductive feedback developed in a commercial 90-nm Si RFCMOS technology. It was demonstrated that division-by-2 operation is achieved with input power down to -12 dBm, with measured locking range of 0.96 GHz (144.18 - 145.14 GHz) at input power of -3 dBm. To the authors' best knowledge, this is the highest operation frequency for ILFD based on a 90-nm CMOS technology. From supply voltage of 1.8 V, the circuit draws 5.7 mA including both core and buffer. The fabricated chip occupies 0.54 mm ${\times}$ 0.69 mm including the DC and RF pads.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.147-150
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• 1990

Methotrexate (MTX)-poly-L-lysine (PLL) conjugate was relatively stable in phosphate buffer of pH 7.4 and in plasma. However, liver homogenate accelerated the release of MTX from the conjugate. Pharmacokinetics and tissue distribution of MTX were compared after intramuscular injection of MTX (treatment I) and MTX-PLL conjugate (treatment II), 10 mg/kg as free MTX to rabbits. The peak concentration of MTX in treatment II were significantly lower than those in treatment I. The amount of MTX excreted in 24-hr urine was significantly reduced in treatment II and it suggested that MTX be more metabolized in treatment II than in treatment I. The amounts of MTX remaining in each organ after 24-hr of intramuscular injection were not significantly different in both treatments.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.811-817
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• 2011

In this study, we have investigated the role of a metal oxide hole injection layer (HIL) between an Indium Tin Oxide (ITO) electrode and an organic hole transporting layer (HTL) in organic light emitting diodes (OLEDs). Nickel Oxide films were deposited at different deposition times of 0 to 60 seconds, thus leading to a thickness from 0 to 15 nm on ITO/glass substrates. To study the influence of NiO film thickness on the properties of OLEDs, the relationships between NiO/ITO morphology and surface properties have been studied by UV-visible spectroscopy measurements and AFM microscopy. The dependences of the I-V-L properties on the thickness of the NiO layers were examined. Comparing these with devices without an NiO buffer layer, turn-on voltage and luminance have been obviously improved by using the NiO buffer layer with a thickness smaller than 10 nm in OLEDs. Moreover, the efficiency of the device ITO/NiO (< 5 nm)/NPB/$Alq_3$/ LiF/Al has increased two times at the same operation voltage (8V). Insertion of a thin NiO layer between the ITO and HTL enhances the hole injection, which can increase the device efficiency and decrease the turn-on voltage, while also decreasing the interface roughness.

• KSBB Journal
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• v.16 no.5
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• pp.459-465
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• 2001

The on-line monitoring technique for the concentrations fo glucose and starch by FIA(Flow Injection Analysis)system was studied. Glucose oxidase(GOD) and amyloglucosidase(AMG) were immboilized on VA-Fpoxy carrier and integrated into the FLA system. The pH, buffer flow rate and temperature were optimized and the effects of salts and metabolites dissolved in the sample on the activity of immobilized enzyme were investigated. GOD-FIA and AMG/GOD-FIA were applied for the on-line monitoring of the glucose and starch in a simulated bioprocess. The on-line measurements of glucose concentrations by GOD-FIA agreed with off-line data well and the AMG/GOD-FIA with single cartidge system took and advantage over the FIA system with two separated cartridges for the on-line monitoring of starch concentrations.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3437-3442
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• 2011

An on-line flow injection analysis with dual pre-concentration method was developed to determine the ultra trace tri and hexavalent chromium in water. In this system, the cation and anion pre-concentration columns were combined with a 10-port injection valve and then used to separate and concentrate Cr (III) and Cr (VI) selectively. The two species of concentrated chromium were sequentially eluted and determined by using HCl-KCl buffer of pH 1.8 as an eluent. Cr (III) was oxidized by hydrogen peroxide to Cr (VI). It was detected spectrophotometrically at 548 nm by complexation with DPC (diphenylcarbazide). Several factors such as concentration of $H_2O_2$, DPC and coil length in reaction condition were optimized. The linear range for Cr (III) and Cr (VI) was 0.1-50 ${\mu}g$/L. The limit of detections ($3{\sigma}$) of Cr (III) and Cr (VI) were 52 ng/L and 44 ng/L under the optimized FIA system, and their recoveries 98% and 103%, respectively. This method was applied to analyze contamination level of chromium species in tap water, groundwater and bottled water.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1070-1073
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• 2003

We have studied the characteristics of organic light-emitting diodes(OLEDs) with the PTFE buffer layer. The OLEDs have been based on the molecular compounds, N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1, 1'- biphenyl-4, 4'-diamine (TPD) as a hole transport, tris(8-hydroxyquinolinoline) aluminum (III) ($Alq_3$) as an electron transport and the Polytetrafluoroethylene (PTFE) as a buffer layer. The devices of structure were fabricated ITO/PTFE/TPD(40nm)/$Alq_3$(60nm)/Al( 150nm) to see the effects of the PTFE buffer layer in organic EL devices. The thickness of the PTFE layer varied from 0.5 to 10[nm]. We were measured Current-Voltage-Luminance Characteristics and Luminance efficiency due to the variation of PTFE thickness. the PTFE layer was reported that helped to enhance the hole tunneling injection and effectively impede induim diffusion from the ITO electrode. We have obtained an improvement of luminance efficiency when the PTFE thickness is 0.5[nm] is used. The improvement of efficiency of is expected due to a function of hole-blocking of PTFE in OLEDs.

• KSBB Journal
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• v.32 no.2
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• pp.103-107
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• 2017

The effect of the trehalose incorporation on the biological membranes was investigated with respect to the phase of the membranes using the fluorescence intensity change. Spherical phospholipid bilayers, vesicles, were prepared only with the variation in the phase of each layer via a double emulsion technique. In the aqueous inside of the vesicles, 8-Aminonaphthalene-1,3,6-trisulfonic acid disodium salt(ANTS) was encapsulated. As a quencher, p-Xylene-bis(N-pyridinium bromide)(DPX) was included in the buffer where the vesicles were dispersed. The fluorescence scale was calibrated with the fluorescence of ANTS vesicles in p-Xylene-bis(N-pyridinium bromide)(DPX)-included-buffer taken as 100% fluorescence and the mixture of ANTS and DPX in the buffer as 0% fluorescence. Trehalose injection into the vesicle solution led the distortion of the membrane. It was found that the distortion was related to the phase of each layer the vesicle up on the ratio of trehalose to lipid. In the identical measurements at glucose, the behavior of the distortion was completely different from that of trehalose. These results seem to depend on the stability of the vesicles, due to the osmotic and volumetric effects on the headgroup packing disruption.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.5
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• pp.409-417
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• 2003

We have studied electrical properties and luminous efficiency of organic light-emitting diodes(OLEDs) with different buffer layer and cathodes in a temperature range of 10 K and 300 K. Four different device structures were made. The OLEDs are based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole transport, tris(8-hydroxyquinolinato) aluminum(III) (Alq$_3$) as an electron transport and omissive layer, and poly(3,4-ethylenedioxythiophene) :poly (styrenesulfonate) (PEDOT:PSS ) as a buffer layer. And LiAl was used as a cathode. Among the devices, the ITO/PEDOT:PSS/TPD/Alq$_3$/LiAl structure has a low energy-barrier height for charge injection and show a good luminous efficiency. We have got a highly efficient and low-voltage operating device using the conductive PEDOT:PSS and low work-function LiAl. From current-voltage characteristics with temperature variation, conduction mechanisms are explained SCLC (space charge limited current) and tunneling one. We have also studied energy barrier height and luminous efficiency at various temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.632-635
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• 2004

We have studied the effect of $TiO_2$ layer deposited by RF magnetron sputtering which is used as an ultra thin hole-injection buffer layer in organic light-emitting diode (OLED). The $TiO_2$ thin film layer prevents metallic ions from diffusing from the ITO layer to the organic layers and improves the balance of hole and electron injections and the interface characteristics between the electrode and the organic layer. With 2 nm thickness of $TiO_2$, the quantum efficiency was improved by 45 % compared to the device fabricated without the $TiO_2$ layer.