• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.58-59
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• 2006

Top emission OLED 소자에 사용되는 ITO(Indium-Tin-Oxide)의 저항을 개선하여 보다 낮은 저항을 가지는 전극을 제작하기 위해 AZO(ZnO-Ag-ZnO)를 제작하였다. AZO박막은 기존의 ITO 박막이 수십 $\Omega$을 나타내던 것과 비교하여 $8{\Omega}$으로 매우 낮은 저항을 나타내었다. 투과율은 84%로 기존의 ITO 박막과 유사한 성능을 나타내었다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.26.1-26.1
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• 2011

We investigated the atomic layer deposition (ALD) process for nitrogen doped ZnO and the application for n-ZnO : N/p-Si (NW) coaxial hetero-junction photodetectors. ALD ZnO:N was deposited using diethylzinc (DEZ) and diluted $NH_4OH$ at $150^{\circ}C$ of substrate temperature. About 100~300 nm diameter and 5 um length of Si nanowires array were prepared using electroless etching technique in 0.108 g of $AgNO_3$ melted 20 ml HF liquid at $75^{\circ}C$. TEM images showed ZnO were deposited on densely packed SiNW structure achieving extraordinary conformality. When UV (360 nm) light was illuminated on n-ZnO:N/p-SiNW, I-V curve showed about three times larger photocurrent generation than film structure at 10 V reverse bias. Especially, at 660 nm wave length, the coaxial structure has 90.8% of external quantum efficiency (EQE) and 0.573 A/W of responsivity.

• Korean Journal of Crystallography
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• v.7 no.2
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• pp.183-190
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• 1996

Single crystals of ZnO were grown hydrothermally with KOH solution in silver lined autoclave. The effect of LiOH and NH4OH on the morphology of as-grown crystals was studied. As-grown crystals were pale green and the maximum size was 30×30×20mm3. Addition of LiOH reduced the density of flaws on the (0001) face of as-grown ZnO crystals. In highly concentrated KOH solution, ZnO had a strong tendency to grow along the c-axis. When 1.0-2.0 M of NH4OH was added into mineralizer, growth rate along the direction of a-axis increased. From this result, ZnO single crystals of equant-faced hexagonal prism could be grown with acicular seeds.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.317-317
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• 2010

ZnO나노와이어는 높은 투과도, 화학 및 열적 안정성을 가지며, 유기태양전지에 적용하였을 때 Active Layer의 표면적 증가, 전자의 수집 및 전달에 용이한 장점가지고 있어 하이브리드 유기 태양전지에 적용되고 있다. ZnO나노와이어와 P3HT/PCBM을 사용한 하이브리드 유기태양전지는 Active Layer의 열처리 온도를 변화시켜 ITO/AZO/ZnO wire/PCBM:P3HT/PEDOT:PSS/Ag구조로 제작되었다. ZnO나노와이어는 AZO를 Seed로 사용하고 Znc nitrate hydrate와 hexamethylenetetramine을 혼합하여 수열합성법으로 성장 후, P3HT:PCBM, PEDOT:PSS을 Spin Coating법으로 형성하였다. UV-vis와 Solar simulator를 통하여 Active Layer의 열처리 온도에 따른 태양전지의 특성을 분석하였다.

• Korean Journal of Materials Research
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• v.32 no.2
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• pp.94-97
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• 2022

We fabricated 3 types of ETL, mp TiO₂, ZnO, and ZnO coated on mp TiO₂(ZMT) to compare the photoelectric conversion efficiency (PCE) and fill factor (FF) of Perovskite solar cells. The structure of the cells was FTO/ETL/Perovskite (CH₃NH₃PbI₃)/spiro-MeOTAD/Ag. SEM morphology assessment of the ETLs showed that mp TiO₂ was porous, ZnO was flat, and the ZMT porous surface was filled with a thin layer. Via XRD measurements, the crystal structures of mp TiO₂ and ZnO ETL were found to be anatase and wurtzite, respectively. The XPS patterns showing energy bonding of mp TiO₂, ZnO, and ZMT O 1s confirmed these materials to be metal oxides such as ETL. The electrical characteristics of the Perovskite solar cells were measured using a solar simulator. Perovskite solar cells with ZMT ETL showed showed PCE of 10.29 % than that of conventional mp TiO₂ ETL devices. This was considered a result of preventing Perovskite from seeping into the ETL and preventing recombination of electrons and holes.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.370-373
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• 2003

A search for a new phosphor composition of excellent performance in systematic ways requires lots of research efforts, and often turns out to be very timeconsuming and difficult. Thus, usually practical ways are taken to improve the performance of phosphors. A few examples of practical surface treatments on phosphors such as $In_2O_3$ coating on $ZnGa_2O_4:Mn$, phosphoric acid treatment on ZnS:Ag,Cl, and base KOH treatment with ultrasonication on ZnS:Ag,Cl are presented. The reasons for the improvement of luminescence intensity or degradation properties after these treatments are discussed based upon careful analyses on the surface of the phosphors and a proposed model on charge carriers generated by electron beam excitation.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.58.1-58.1
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• 2010

Stainless Steel의 유연한 기판을 사용하여 ZnO:Al/Ag의 후면전극에서 Ag 증착 실험조건 변화를 통해서 light trapping을 개선한 n-i-p 구조의 플렉서블 미세결정질 실리콘 박막 태양전지를 제작하였다. 실험 방법으로 마그네트론 스퍼터를 사용하여 Stainless Steel 기판 위에 ZnO:Al/Ag를 증착하여 후면전극으로 사용되는 back reflector를 제작하였으며 그 위에 미세결정질 실리콘 박막을 증착하였다. Back reflector에서 Ag 박막의 증착 온도가 증가할수록 표면결정 성장으로 roughness가 증가하여 반사도를 증가하였다. 또한, Ag 박막 증착 두께와 압력 변화에 따른 광학적 특성변화를 Atomic Force Microscope(AFM), Scanning Electron Microscopy(SEM),UV-visible-nIR spectrometry로 조사하여 최적의 조건을 찾았으며 개선된 back reflector의 특성이 n-i-p 구조의 플렉서블 미세결정질 실리콘 박막 태양전지에 적용하여 light trapping의 증가가 태양전지에서 광학적인 특성 변화 및 효율 향상에 영향을 주는지 Photo IV와 EQE(External Quantum Efficiency)를 통하여 조사하였다.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.17-23
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• 2015

Objectives: The cytotoxcities of Au, Ag, SWCNT, $SiO_2$, and ZnO nanomaterials were evaluated in order to assess their potential toxicological effects in in vitro cell models using colony forming efficiency (CFE) assay. Methods: The CFE assay of the test materials was carried out on Hep G2 cells. The size distribution of nanomaterials was studied by transmission electron microscopy (TEM). Changes in cell viability after treatment with a toxicant will result in a decreased number of colonies formed in comparison to solvent. Results: The TEM images show that all the particles except SWCNT and ZnO can be considered approximately spherical. The gold and $SiO_2$ nanoparticles show no response (no toxicity) in concentration response experiments. A statistically significant toxic effect was found in Hep G2 cells treated with Ag, SWCNT and ZnO nanomaterials. Conclusion: In this study, we considered CFE assay to be a promising test for screening studies for cytotoxicity with physicochemical analysis.

• Environmental Engineering Research
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• v.20 no.4
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• pp.329-335
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• 2015

The effects of ion-doping on $TiO_2$ nanotubes were investigated to obtain the optimal catalyst for the effective decomposition of Rhodamine B (RB) through UV photocatalytic oxidation process. Changing the calcination temperature, which changed the weight fractions of the anatase phase, the average crystallite sizes, the BET surface area, and the energy band gap of the catalyst, affected the photocatalytic activity of the catalyst. The ionic radius, valence state, and configuration of the dopant also affected the photocatalytic activity. The photocatalytic activities of the catalysts on RB removal increased when $Ag^+$, $Al^{3+}$ and $Zn^{2+}$ were doped into the $TiO_2$ nanotubes, whereas such activities decreased as a result of $Mn^{2+}$ or $Ni^{2+}$ doping. In the presence of $Zn^{2+}$-doped $TiO_2$ nanotubes calcined at $550^{\circ}C$, the removal efficiency of RB within 50 min was 98.7%.

• Journal of the Korean Electrochemical Society
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• v.6 no.4
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• pp.242-249
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• 2003

Zn electrode was widely used as an anode material in alkaline battery systems in highly concentrated KOH electrolyte, however it was well known that its cycle life is significantly shortened by growth of dendrite due to the high dissolution of $Zn(OH)_2$ and rapid electrochemical reaction. In this study when by the additives such as $Ca(OH)_2$, Citrate, tartrate and Gluconate were added to $40\%$ KOH electrolyte at solution temperature of $25^{\circ}C$ and the amount of $5wt\%\;Pb_3O_4$ was mixed to Zn electrode and then the effect of $Pb_3O_4$ and additives on the electrochemical behavior of Zn electrode was investigated by Potentiodynamic Polarization Curves, Cyclic Voltammetry, Accelerated Life Cycle lest, and SEM image analyses. The addition of $Pb_3O_4$ reduced the corrosion rate of Zn electrode. The corrosion potential of Zn electrode with $Pb_3O_4$ was higher or lower than that of pure Zn electrode however was not influenced practically to the open circuit voltage. And the addition of 4 type additives had an important role in improving both cycle life in accelerated cycle life test and corrosion resistance. Furthermore the additive of Tartrate indicated comparatively a good effect to corrosion resistance as well as charging-discharging property Improvement among those four type additives.