• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.485-487
• /
• 2008

By the oxygen plasma exposure to the organic light-emitting diodes, the turn-on voltage decreased from 10.5 to 7 V and luminance increased from 470 to $852\;cd/m^2$. Synchrotron radiation photoelectron spectroscopy results showed that during oxygen plasma exposure, oxygen ions were diffused into organic layer and induced p-type doping effect.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제52권6호
• /
• pp.261-266
• /
• 2003

We investigated the effect of oxygen plasma treatment of indium-tin oxide(ITO) surface on the performance of electroluminescence(EL) devices. ITO surface treated oxygen plasma has been analyzed using atomic force microscope(AFM) and X-ray photoelectron spectroscopy(XPS), to investigate the relations between the properties of the ITO surface and the properties of the current-voltage-luminance(I-V-L) characteristics of the fabricated OLED with the structure of ITO(plasma treatment) / TPD / Alq$_3$/ Al. It is found that the oxygen plasma treatment of ITO anode improve the hole injection of the OLED due to the modification of the surface states. The treated ITO anode nay be low voltage with high luminance efficiency.

• 한국정밀공학회지
• /
• 제27권12호
• /
• pp.113-118
• /
• 2010

For a present study, woven type carbon fibers were surface-modified by oxygen plasma to improve adhesive strength between carbon fibers and epoxy. The change of hydrophilic properties by the plasma modification was investigated through the contact angle measurement and the calculation of surface energy of carbon fiber due to the oxygen plasma modification. FESEM and XPS analyses were performed to study the chemical and physical changes on the surface of carbon fibers due to the oxygen plasma modification. Pin-on-disk wear tests were conducted under dry condition using unmodified and plasma-modified carbon/epoxy composites to investigate the effect of plasma modification on the wear behavior of woven type carbon/epoxy composites. The results showed that the friction coefficient and the wear rate of plasma-modified carbon/epoxy composites were lower than those of unmodified carbon/epoxy composites, respectively. XPS analysis showed that new functional group of a carbonyl type was created on the carbon fibers by the $O_2$ plasma treatment, which enhanced adhesive strength between carbon fibers and epoxy, leading to improve wear properties

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
• /
• pp.80-83
• /
• 2005

In this work, effects of oxygen plasma on surface characteristics of carbon fibers were investigated in mechanical properties interfacial of carbon fibers-reinforced composites. The surface properties of the carbon fibers were determined by acid/base values, FT-IR, and X-ray photoelectron spectroscopy (XPS). Also, the mechanical properties of the composites were studied in and critical stress intensity factor ($K_{IC}$) and critical strain energy release rate mode II ($G_{IIC}$) measurements. As experimental results, the $O_{lS}/C_{lS}$ ratio of the carbon fiber surfaces treated by oxygen plasma was increased compared to that of untreated ones, possibly due to development of oxygen-containing functional groups. The mechanical properties of the composites, including $K_{IC}$ and $G_{IIC}$ had been improved in the oxygen plasma on fibers. These results could be explained that the oxygen plasma was resulted in the increase of the adhesion of between fibers and matrix in a composite system.

• 한국환경과학회지
• /
• 제20권7호
• /
• pp.907-917
• /
• 2011

This study investigated the application of experimental design methodology to optimization of conditions of air-plasma and oxygen-plasma oxidation of N, N-Dimethyl-4-nitrosoaniline (RNO). The reactions of RNO degradation were described as a function of the parameters of voltage ($X_1$), gas flow rate ($X_2$) and initial RNO concentration ($X_3$) and modeled by the use of the central composite design. In pre-test, RNO degradation of the oxygen-plasma was higher than that of the air-plasma though low voltage and gas flow rate. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and test variables in a coded unit: RNO removal efficiency (%) = $86.06\;+\;5.00X_1\;+\;14.19X_2\;-\;8.08X_3\;+\;3.63X_1X_2\;-\;7.66X_2^2$ (air-plasma); RNO removal efficiency (%) = $88.06\;+\;4.18X_1\;+\;2.25X_2\;-\;4.91X_3\;+\;2.35X_1X_3\;+\;2.66X_1^2\;+\;1.72X_3^2$ (oxygen-plasma). In analysis of the main effect, air flow rate and initial RNO concentration were most important factor on RNO degradation in air-plasma and oxygen-plasma, respectively. Optimized conditions under specified range were obtained for the highest desirability at voltage 152.37 V, 135.49 V voltage and 5.79 L/min, 2.82 L/min gas flow rate and 25.65 mg/L, 34.94 mg/L initial RNO concentration for air-plasma and oxygen-plasma, respectively.

• 한국표면공학회지
• /
• 제32권3호
• /
• pp.344-350
• /
• 1999

The surface chemical structure of three kinds of polyethylene (PE): high density (HD) PE, low density (LD) PE and linear (L)-LDPE exposed to Ar and $O_2$ plasmas has been investigated using XPS. Oxygen was incorporated in a more increased amount for HDPE than for L-LDPE and LDPE. Ar plasma tended to incorporate more oxygen than $O_2$ plasma. The XPS valence band spectra for Ar plasma exhibited a clear peak assigned to $O_2$s character. By chemical derivatization method it was found that the amount of -COOH group at the surface was much greater than that of -OH group. The hydrophilic nature of plasma-treated PE increased in the order: LDPE

• 한국전기전자재료학회논문지
• /
• 제33권6호
• /
• pp.454-459
• /
• 2020

In this study, a TiO₂/TiO_2-x-based resistance variable memory was fabricated using a DC/RF magnetron sputtering system and ALD. In order to analyze the effect of oxygen plasma treatment on the performance of resistance random access memory (ReRAM), the TiO₂/TiO_2-x-based ReRAM was evaluated by applying RF power to the TiO_2-x oxygen-holding layer at 30, 60, 90, 120, and 150 W, respectively. The ReRAM was fabricated, and the electrical and surface area performances were compared and analyzed. In the case of ReRAM without oxygen plasma treatment, the I-V curve had a hysteresis curve shape, but the width was very small, with a relatively high surface roughness of the oxygen-retaining layer. However, in the case of oxygen plasma treatment, the HRS/LRS ratio for the I-V curve improved as the applied RF power increased; stable improvement was also noted in the surface roughness of the oxygen-retaining layer. It was confirmed that the low voltage drive was not smooth due to charge trapping in the oxygen diffusion barrier layer owing to the high intensity ReRAM applied with an RF power of approximately 150 W.

• Fibers and Polymers
• /
• 제6권2호
• /
• pp.113-120
• /
• 2005

Helium-oxygen plasma treatments were conducted to modify poly(trimethylene terephthalate) (PIT) and poly(ethylene terephthalate) (PET) warp knitted fabrics under atmospheric pressure. Lubricant and contamination removals by plasma etching effect were examined by weight loss $(\%)$ measurements and scanning electron microscopy (SEM) analysis. Surface oxidation by plasma treatments was revealed by x-ray photoelectron spectroscopy (XPS) analyses, resulting in formation of hydrophilic groups and moisture regain $(\%)$ enhancement. Low-stress mechanical properties (evaluated by Kawabata evaluation system) and bulk properties (air permeability and bust strength) were enhanced by plasma treatment. Increasing interfiber and interyarn frictions might play important roles in enhancing surface property changes by plasma etching effect, and then changing low-stress mechanical properties and bulk properties for both fabrics.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.118-120
• /
• 2009

We reported that the evidence of oxygen doping to copper-phthalocyanine (CuPc) by $O_2$-plasma treatment to Au electrode of inverted top emitting organic light emitting diodes (ITOLEDs). The operation voltage of OLEDs at 150 mA/$cm^2$ decreased from 16.1 to 10.3 V as oxygen atoms indiffued to CuPc layer using $O_2$-plasma. Synchrotron radiation photoelectron spectroscopy results showed that a new bond of Cu-O appeared and the energy difference between the highest occupied molecular orbital and $E_F$ is lowered by 0.20 eV after plasma treatment. Thus the hole injection barrier was lowered, reducing the turn-on voltage and increasing the quantum efficiency of OLEDs.

• 한국재료학회지
• /
• 제14권5호
• /
• pp.363-367
• /
• 2004

Recently ZnO epitaxial layers have been widely studied as a semiconductor material for optoelectronic devices. Sapphire and silicon are commonly selected as substrate materials for ZnO epitaxial growth. In this communication, we report the effect of the ECR plasma pretreatment of sapphire and silicon substrates on the nucleation in the ZnO ALE (atomic layer epitaxy). It was found that ECR plasma pretreatment reduces the incubation period of the ZnO nucleation. Oxygen ECR plasma enhances ZnO nucleation most effectively since it increases the hydroxyl group density at the substrate surface. The nucleation enhancing effect of the oxygen ECR plasma treatment is stronger on the sapphire substrate than on the silicon substrate since the saturation density of the hydroxyl group is lower at the sapphire surface than that at the silicon surface.