• Journal of the Korean institute of surface engineering
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• v.41 no.3
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• pp.102-108
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• 2008

In this paper, the LiF and polymer thin film as passivation layer have been evaporated on green OLED devices. HDPE, polyacenaphthylene, polytetrafluoroethylene, poly(2,6-dimethyl-1,4-pheneylene oxide), poly sulfone and poly(dimer-acid-co-alkyl poly-amine) have been used as polymer materials. The optical transmittance of evaporated polymer thin film was very good as an above 90% in visible range. The morphology of polymer thin film was measured by AFM. As a result of the measurement average roughness($R_a$) value of the polysulfone was very low as 2.2 nm. The green OLED devices with a structure of ITO/HIL/HTL/EML/Buffer/Al in series of various passivation films were fabricated and analyzed. It was observed that an OLED device with LiF as first passivation film has shown the good electrical and optical property, and all kind of polymer films did not influence on the I-V-L characteristics and the life time of OLED devices. Therefore, we found that polymer layer played a key role as a buffer layer between the inorganic passivation layers to relieve the stress of the inorganic layers.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.51-55
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• 2011

The surface passivation is one of the important methods that can improve the efficiency of solar cells and can be classified into two methods: wet-chemical passivation and film passivation. In this paper, chemical HF treatment were employed for the passivation of n-type silicon wafers and their effects were studied. To investigate film passivation effects, the silicon nitride films were also deposited by PECVD (plasma-enhanced chemical vapor deposition) on n-type silicon wafers treated with chemical HF. The minority carrier lifetime measurements were used for evaluation of the passivation characteristics in the all experiments steps. We confirmed that the minority carrier lifetime was improved with chemical HF treatment due to passivation effects by H-termination.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.6
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• pp.321-326
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• 2016

Minimizing the carrier recombination and electrical loss through surface passivation is required for high efficiency c-Si solar cell. Usually, $SiN_X$, $SiO_X$, $SiON_X$ and $AlO_X$ layers are used as passivation layer in solar cell application. Silicon oxide layer is one of the good passivation layer in Si based solar cell application. It has good selective carrier, low interface state density, good thermal stability and tunneling effect. Recently tunneling based passivation layer is used for high efficiency Si solar cell such as HIT, TOPCon and TRIEX structure. In this paper, we focused on silicon oxide grown by various the method (thermal, wet-chemical, plasma) and passivation effect in c-Si solar cell.

• Electrical & Electronic Materials
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• v.10 no.5
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• pp.473-480
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• 1997

Surface passivation using glass powders results in good reliability for high voltage silicon power devices. In this paper Zinc borosilicate glass and Lead borosilicate glass were prepared for the purpose of passivating, and a deposition technique of glass films on the silicon surface by electrophoresis in which acetone is used as a suspension medium has been investigated. Their physical properties were compared using DTA, SEM, XRD, as a function of firing temperature, I can get the fine films of 22${\mu}{\textrm}{m}$ thickness with Lead borosilicate glass under 300 volts applied, 3 minutes and $700^{\circ}C$ firing temperature. Also I can get the fine films of 17${\mu}{\textrm}{m}$ thickness with Zinc borosilicate glass under same conditions. As a result of investigation of glass films from which glass layer was removed by placing it in HCl, it has been found that pre-firing and annealing play an important role to achieve uniform and fine glass deposition films. And also it was found that relative dielectric constant is independence of frequency.

• Journal of the Korean institute of surface engineering
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• v.36 no.3
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• pp.251-255
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• 2003

With increasing environmental demands in surface treatment of steel sheets, the passivation layers containing hexavalent chromium $(Cr^{+6})$ are being replaced by non-chromium or trivalent chromium compounds. After review on the various types of inorganic compounds, the zirconates was chosen as the candidate for alternative to sodium dichromate in the aspect of its barrier properties with excellent adhesion to organics. The ammonium zirconium carbonate (AZC) and sodium hexafluorozirconate (SFZ) could be reach $70-80\%$ level of CDC (cathodic dichromate) treatment by their single applications. But high porosity in the AZC layer and poor electrical conductivity of SFZ solution limit the single application of zirconate. Mixed composition of zirconates to compensate their inferiorities or incorporation of organic compounds to seal the porosity seems to be inevitable to match up the target level of Cr-free passivation of tinplate.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1642-1644
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• 1996

Passivation must prevent ionic charge movement on the surface of the junction, thereby minimizing the junction leakage and maximizing the breakdown voltage of the devices. Borosilicate glasses are widely used as surface passivants for such silicon power devices as thyristors, transistor, and diodes. Since these 91asses are electrically stable at high temperatures and in high electric fields, they can readily be applied as a thick film, and they are resistant to humidity and have low ionic mobility. A deposition technique of glass film on the silicon surface by electrophoresis in which acetone is used as a suspension medium has been investigated. The purpose of this paper is to describe electrophoretic deposition method for glass passivation and characteristics of glass films which were compared using DTA, SEM, XRD, as a function of firing temperature.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.98-99
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• 2014

질산산화법(nitric acid oxidation method)은 저온에서 안정적인 산화막을 형성하는 직접산화공정으로 azeotropic point(68 wt%)인 120도 이하의 온도에서 산화막을 형성한다. 120도에서 형성한 질산산화막은 CVD법으로 형성한 산화막 보다 낮은 누설전류밀도(leakage current density)를 나타낸다. 또한 질산의 농도가 증가함에 따라 형성한 산화막의 누설전류밀도가 감소하며, 이는 열산화법으로 형성한 산화막 보다 낮다. 질산산화의 낮은 누설전류밀도는 형성한 산화막의 높은 원자 밀도와 낮은 계면준위밀도에 의한 것으로 이 특성을 이용하여 게이트 절연막(gate insulator)과 태양전지의 passivation막으로 응용되고 있다.

• Journal of the Semiconductor & Display Technology
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• v.12 no.3
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• pp.41-46
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• 2013

Efficient and inexpensive solar cells are necessary for photo-voltaic to be widely adopted for mainstream electricity generation. For this to occur, the recombination losses of charge carriers (i.e. electrons or holes) must be minimized using a surface passivation technique suitable for manufacturing. Recently it has been shown that aluminum oxide thin films are negatively charged dielectrics that provide excellent surface passivation of silicon solar cells to attract positive-charged holes. Especially aluminum oxide thin film is a quite suitable passivation on the rear side of p-type silicon solar cells. This paper, it demonstrate the interfacial microstructure and electrical properties of mono-crystalline silicon surface passivated by $Al_2O_3$ films during firing process as applied for screen-printed solar cells. The first task is a comparison of the interfacial microstructure and chemical bonds of PECVD $Al_2O_3$ and of PEALD $Al_2O_3$ films for the surface passivation of silicon. The second is to study electrical properties of double-stacked layers of PEALD $Al_2O_3$/PECVD SiN films after firing process in the temperature range of $650{\sim}950^{\circ}C$.

• ETRI Journal
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• v.21 no.3
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• pp.16-21
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• 1999

After etching Al-Cu alloy films using SiCl4/Cl_2/He/CHF3 mixed gas plasma, the corrosion phenomenon at the grain boundary of the etched surface and a passivation layer on the etched surface with an SF6 plasma treatment subsequent to the etching were studied. In Al-Cu alloy system, corrosion occurs rapidly on the etched surface by residual chlorine atoms, and it occurs dominantly at the grain boundaries rather than the crystalline surfaces. To prevent corrosion, the SF6 gas plasma treatment subsequent to etching was carried out. The passivation layer is composed of fluorine-related compounds on the etched Al-Cu surface after the SF6 treatment, and it suppresses effectively corrosion on the surface as the SF6 treatment pressure increases. Corrosion could be suppressed successfully with the SF6 treatment at a total pressure of 300 mTorr. To investigate the reason why corrosion could be suppressed with the SF6 treatment, behaviors of chlorine and fluorine were studied by various analysis techniques. It was also found that the residual chlorine incorporated at the grain boundary of the etched surface accelerated corrosion and could not be removed after the SF6 plasma treatment.

• Corrosion Science and Technology
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• v.8 no.6
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• pp.209-216
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• 2009

In this study the effect of different surface finishing techniques on the pitting corrosion behaviour of a commercial 304 stainless steel alloy was investigated. Surface finishing methods were divided into two categories, i.e. mechanical and chemical. Mechanical treatment methods include power tooling such as grinding, emery paper brushing, stainless steel wire brushing and stainless steel shot blasting. Chemical treatment methods include chemical passivation (phosphoric acid, citric acid, nitric acid) and electro-cleaning (phosphoric acid and citric acid). Potentiodynamic polarization experiments were carried out in 3.5 wt. % NaCl solution at room temp. (20 $^{\circ}C$). The results showed that chemical treatment methods improved the corrosion resistance of stainless steel 304, measured in terms of pitting potential ($E_{pit}$). Corrosion resistance of the specimens was increased in the order of; electro-cleaning > manual passivation > mechanical cleaning. Surface of electro-cleaned specimens was smoother than rest of the surface treatment methods. Chrome content in chemically treated specimens was higher than in mechanically treated specimens as shown by EDX analysis.