• Transactions on Electrical and Electronic Materials
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• 제10권3호
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• pp.89-92
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• 2009

High-quality Al-N doped p-type ZnO thin films were deposited on Si and buffer layer/Si by DC magnetron sputtering in a mixture of $N_2$ and $O_2$ gas. The target was ceramic ZnO mixed with $Al_2O_3$ (2 wt%). The p-type ZnO thin films showed a carrier concentration in the range of $1.5{\times}10^{15}{\sim}2.93{\times}10^{17}\;cm^{-3}$, resistivity in the range of 131.2${\sim}$2.864 ${\Omega}cm$, mobility in the range of 3.99${\sim}$31.6 $cm^2V^{-1}s^{-l}$, respectively. It was easier to dope p-type ZnO films on Si substrates than on buffer layer/Si. The film grown on Si showed the highest quality of photoluminescence (PL) characteristics. The Al donor energy level depth $(E_d)$ of Al-N codoped ZnO films was reduced to about 50 meV, and the N acceptor energy level depth $(E_a)$ was reduced to 63 meV.

• 한국산업보건학회지
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• 제5권2호
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• pp.119-127
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• 1995

The purpose of this study was to determine the effects of surface-treatment by zinc salts on break-through and adsorption capacity of toluene. Firstly, the coconut activated carbon treated the surface with zinc salts, were exposed by the spike sample(toluene, 69.02ppm, $260.1mg/m^3$), and then the effects of zinc salts were examined by using the gas adsorption kinetics. The results obtained were as follows : 1) BET(Brumaure Emmett Teller) surface area were $954.4m^3/g$ in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and $830.3m^2/g$ in coconut activated carbon treated with 0.0001 N $ZnCl_2$. 2) Migration was decreased in coconut activated carbon treated with the thin level of zinc salts. 3) Breakthrough volume were 73.07 L in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and 72.76 L in charcoal treated with 0.0001 N $ZnCl_2$. 4) ${\tau}$ values(the time required for 50% breakthrough) were 1046.1 min in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 921.2 min in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. 5) Maximum adsorption capacity was 53.9 mg/tube in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 47.4 mg/tube in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. In conclusion, the coconut activated carbon treated the surface with the thin concentration of zinc salts, decreased the breakthrough and increased the BET surface area and the adsorption capacity in case of sampling airborne toluene.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권3호
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• pp.125-130
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• 2006

The optical gain and the luminescence of a ZnO quantum well with MgZnO barriers is studied theoretically. We calculated the non-Markovian optical gain and the luminescence for the strained-layer wurtzite quantum well taking into account of the excitonic effects. It is predicted that both optical gain and luminescence are enhanced for the ZnO quantum well when compared with those of InGaN-AlGaN quantum well structure due to the significant reduction of the piezoelectric effects in the ZnO-MgZnO systems.

• 전자공학회논문지D
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• 제34D권2호
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• pp.27-37
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• 1997

Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and $Si_3N_4$ powders were used to synthesize $(Mg_xZn_{1-x})SiN_2$ host materials. $Tb_4O_7$ and $Eu_2O_3$ powdrs were added as luminescent centers. Very sharp emission spectra of $Tb^{3+}$ ions were observed from $Mg._5Zn._5SiN_2:Tb$ sampels sintered at $1400^{\circ}C$ for an hour and the maximum intensity of emission spectra occured at wavelength of 550nm (green light). Synthetic conditions of $(Mg_xZn_{1-x})SiN_2:Eu$ phosphors were optimized for the hghest luminescence. The Eu concentrations were varied from 0.2% to 1.6%. Before firing, the powders were mixed using ballmills, methanol, acetone, or D.I. water. The Mg/Zn ratio also were varied from x=0.3 to x=0.7. The maximum PL intensity was obtained from a sample with 1.2% Eu concentration and the powder was mixed with methanol and dried before firing. The maximum intensity of the emission spectra occurred t the wavelength of 470nm(blue light). TFEL devices fabricated by using sputter deposition of $(Mg._3Zn._7)SiN_2:Eu$ phosphor layer showed yellowish white emission at the phosphor field of 2MV/cm.

• Journal of Electrochemical Science and Technology
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• 제12권2호
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• pp.173-187
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• 2021

In the present research, a simple electrochemical sensor based on a carbon paste electrode (CPE) modified with ZnO-Zn₂SnO₄-SnO₂ and graphene (ZnO-Zn₂SnO₄-SnO₂/Gr/CPE) was developed for the direct, simultaneous and individual electrochemical measurement of Acetaminophen (AC), Caffeine (Caf) and Ascorbic acid (AA). The synthesized nano-materials were investigated using scanning electron microscopy, X-ray Diffraction, Fourier-transform infrared spectroscopy, and electrochemical impedance spectroscopy techniques. Cyclic voltammetry and differential pulse voltammetry were applied for electrochemical investigation ZnO-Zn₂SnO₄-SnO₂/Gr/CPE, and the impact of scan rate and the concentration of H⁺ on the electrode's responses were investigated. The voltammograms showed a linear relationship between the response of the electrode for individual oxidation of AA, AC and, Caf in the range of 0.021-120, 0.018-85.3, and 0.02-97.51 μM with the detection limit of 8.94, 6.66 and 7.09 nM (S/N = 3), respectively. Also, the amperometric technique was applied for the measuring of the target molecules in the range of 0.013-16, 0.008-12 and, 0.01-14 μM for AA, AC and, Caf with the detection limit of 6.28, 3.64 and 3.85 nM, respectively. Besides, the ZnO-Zn₂SnO₄-SnO₂/Gr/CPE shows an excellent selectivity, stability, repeatability, and reproducibility for the determination of AA, AC and, Caf. Finally, the proposed sensor was successfully used to show the amount of AA, AC and, Caf in urine, blood serum samples with recoveries ranging between 95.8% and 104.06%.

• 대한화학회지
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• 제18권3호
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• pp.194-201
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• 1974

네자리 schiff리간드는 salicylaldehyde와 m-phenylenediamine을 Duff-반응 시킴으로써 N,N-bis(salicylaldehyde)-m-phenylenediimine을 합성하고 이 리간드와 Cu(II), Ni(II), Co(II) 및 Zn(II) 이온들과의 새로운 착물 Cu(II)$[C_{20}H_{14}O_2N_2]{\cdot}2H_2O, Co(II)[C_{20}H_{14}O_2N_2]{\cdot}2H_2O$ 및 Zn(II)$[C_{20}H_{14}O_2N_2]{\cdot}4H_2O$들을 합성하였다. 이들 착물에 대하여 가시부 흡수스펙트럼, 적외선스펙트럼, TGA, X-ray 회절 및 원소분석 결과에 의하여 Cu(II), Ni(II) 및 Co(II) 착물들은 리간드와 금속이 1:1 몰비 및 2수화물의 6배위 착물로 주어지며 Zn(II) 착물은 1:2 몰비 4배위 착물로 주어짐을 알았다

• 한국초지조사료학회지
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• 제24권1호
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• pp.1-10
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• 2004

Orchardgrass 및 white clover의 단파 및 혼파 재배조건에서 미량요소 Fe, Mn, Cu, Zn, Mo및 B의 조합시비가 목초의 생육, 개화, 수량, 양분 함량 및 식생구성비율 등에 미치는 영향을 구명하였다. 다량요소 양분을 동일 량 시비한 조건에서 7 수준의 미량요소 조합시비는 $T_1$; 대조구, $T_2$; Fe, $T_3$; Fe+Mn, $T_4$; Fe+Mn＋Cu, $T_5$ ; Fe＋Mn＋Cu＋Zn, $T_6$ ; Fe＋Mn＋Cu＋Zn＋Mo 및 $T_{7}$ ; Fe＋Mn＋Cu＋Zn＋Mo＋B로 하였다. 본 III보에서는 조합시비가 목초의 N-화합물(조/순단백질 및 수용성 N-화합물)의 함량 및 이들의 수량(함량<%>/100 ${\times}$ 건물수량) 등에 미치는 영향을 검토하였다. 1. N-화합물의 함량은 일반적으로 초종(grass-clover), 재배방법(단파/혼파) 및 추비의 시비여부별 큰 차이를 보였다. Orchardgrass에서 처리별 N-화합물의 함량차이는 경미하였으나 $T_3$와 $T_6$ 에서는 단파 및 혼파재배 공히 다소 낮은 경향을 보였다. White clover에서는 처리별 차이가 단파재배에서는 뚜렷하지 않았으나 혼파재배에서는 $T_1$, $T_3$ 및 $T_6$ 에서 다소 낮은 부정적인 영향을 보였다. 2. 처리별 건물수량에 미치는 효과보다 조/순단백질의 수량에 미치는 효과가 상대적으로 더 컸으며 이는 orchardgrass의 경우보다 white clover에서 더 큰 영향을 보였다. 처리별 조단백질의 수량차이를 보면 orchardgrass는 건물수량의 변화특성과 상대적으로 비슷한 경향을 보였으나 조단백질의 수량에 미치는 $T_3$와 $T_6$의 부정적인 효과는 건물수량의 경우보다 더 크게 나타났다. 3. White clover에서 처리별 조단백질의 수량차이는 특히 혼파재배와 무추비 5차 예취 시에 뚜렷한 차이를 보였다. 추비(특히 N)가 조단백질의 수량에 미치는 조합시비의 효과를 경감시켰다. 또한 혼파재배에서 적합한 조합시비에 따른 white clover의 양호한 생육은 N-화합물의 양호한 함량 및 수량과 밀접한 연관성을 갖는 것으로 보였다. 두 초종 공히 처리별 순단백질의 수량변화 특성은 상술한 조단백질의 변화 특성과 비슷한 경향을 보였다.

• 한국세라믹학회지
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• 제32권8호
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• pp.938-944
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• 1995

Dielectric properties and the stabilization of perovskite phase for the (1-y)Pb(Mg(1-x)/3Znx/3Znx/3Nb2/3)O3-yBaTiO3 ((1-y)PM1-xZxN-yBT) ceramics have been investigated as a function of amount of x and y. In the (1-y)PM0.6Z0.4N-yBT ceramics, the amount of pyrochlore phae was decreased by the addition of 2 mol% BT and the dielectric constant was increased. However, the dielectric constant decreased with further addition of BT even though pyrochlore phase was decreased. Dielectric prooperties in (1-y)PM0.6Z0.4N-yBT ceracmis were affected by the character of the BT rather than the amount of pyrochlore phase. The phase transitions were broadened and phase transition temperatures were lowered by the increase of BT contents.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.242-246
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• 2006

Background level of heavy metals In soils (316 points by 15 classifications of land use) was investigated by two test methods, 0.1N HCl(1N HCl for As) extraction and aqua regia extraction methods. The average concentrations of aqua regia extractable heavy metals in soil(n=316) was 6.24(As), 0.25(Cd), 37.99(Cr), 24.10(Cu), 0.04(Hg), 25.68(Pb), 22.59(Ni), 106.11(Zn) mg/kg, respectively. Also the average concentrations of 0.1N HCl extractable heavy metals was 0.06(As), 0.08(Cd), 0.27(Cr), 3.78(Cu), 4.02(Pb), 12.5(Zn), 0.58(Ni) mg/kg, respectively. The ratio of soluble contents and total contents were 2.6%(As), 32.7%(Cd), 0.7%(Cr), 15.7%(Cu), 15.7%(Pb), 2.6%(Ni), 11.8%(Zn), and the correlation coefficient of soluble contents and total contents were 0.26(As), 0.27(Cd), 0.22(Cr), 0.57(Cu), 0.42(Pb), 0.23(Ni), 0.72(Zn).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.419-420
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• 2008

In this study, high quality (Al,N)-codoped p-type ZnO thin films were obtained by DC magnetron sputtering. The film on buffer layer grown in 80% $N_2$ ambient shows highest hole concentration of $2.93\times10^{17}cm^{-3}$. The films show hole concentration in the range of $1.5\times10^{15}$ to $2.93\times10^{17}cm^{-3}$, resistivity of 131.2 to 2.864 $\Omega$cm, mobility of 3.99 to 31.6 $cm^2V^{-1}s^{-1}$. The films on Si show easier p-doping in ZnO than those on buffer layer. The film on Si shows the highest quality of optical photoluminescence (PL) characteristics. The donor energy level $(E_d)$ of (Al,N)-codoped ZnO films is about 50 meV and acceptor energy level $(E_a)$ is in the range of 63 to 71 meV. It will help to improve p-type ZnO films.