• Solar Energy
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• v.17 no.3
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• pp.51-57
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• 1997

Cu-doped ZnTe thin films have been grown by hot-wall evaporation. The electrical conductivity of the intrinsic ZnTe film was of p-type and as low as $10^{-6}({\Omega}{\cdot}cm)^{-1}$. As the doped Cu concentration was increased, the electrical conductivity was increased. up to $10^2({\Omega}{\cdot}cm)^{-1}$, but the mobility was decreased a little. The heavily doped sample shows the metal-like electrical resistivity.

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.185-187
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• 2012

Ga doped ZnO (GZO)/copper (Cu) bi-layered film was deposited on glass substrate by RF and DC magnetron sputtering and then the effect of the Cu bottom layer on the optical, electrical and structural properties of GZO films were considered. As-deposited 100 nm thick GZO films had an optical transmittance of 82% in the visible wavelength region and a sheet resistance of 4139 ${\Omega}/{\Box}$, while the GZO/Cu film had optical and electrical properties that were influenced by the Cu bottom layer. GZO films with 5 nm thick Cu film show the lower sheet resistance of 268 ${\Omega}/{\Box}$ and an optical transmittance of 65% due to increased optical absorption by the Cu metallic bottom layer. Based on the figure of merit, it can be concluded that the thin Cu bottom layer effectively increases the performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.118-118
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• 2011

The Nano-Floating Gate Memory(NFGM) devices with ZnO:Cu thin film embedded in Al2O3 and AlOx-SAOL were fabricated and the electrical characteristics were evaluated. To further improve the scaling and to increase the program/erase speed, the high-k dielectric with a large barrier height such as Al2O3 can also act alternatively as a blocking layer for high-speed flash memory device application. The Al2O3 layer and AlOx-SAOL were deposited by MLD system and ZnO:Cu films were deposited by ALD system. The tunneling layer which is consisted of AlOx-SAOL were sequentially deposited at $100^{\circ}C$. The floating gate is consisted of ZnO films, which are doped with copper. The floating gate of ZnO:Cu films was used for charge trap. The same as tunneling layer, floating gate were sequentially deposited at $100^{\circ}C$. By using ALD process, we could control the proportion of Cu doping in charge trap layer and observe the memory characteristic of Cu doping ratio. Also, we could control and observe the memory property which is followed by tunneling layer thickness. The thickness of ZnO:Cu films was measured by Transmission Electron Microscopy. XPS analysis was performed to determine the composition of the ZnO:Cu film deposited by ALD process. A significant threshold voltage shift of fabricated floating gate memory devices was obtained due to the charging effects of ZnO:Cu films and the memory windows was about 13V. The feasibility of ZnO:Cu films deposited between Al2O3 and AlOx-SAOL for NFGM device application was also showed. We applied our ZnO:Cu memory to thin film transistor and evaluate the electrical property. The structure of our memory thin film transistor is consisted of all organic-inorganic hybrid structure. Then, we expect that our film could be applied to high-performance flexible device.----못찾겠음......

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.70-75
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• 2001

The purpose of this study is to investigate the effect of V₂O/sub 5/ addition on physical and magnetic properties of NiCuZn ferrite for multi-layer chip inductors. NiCuZn ferrite pastes doped with 0, 0.1, 0.3 and 0.5 wt% V₂O/sub 5/ were prepared and samples of ferrite sheets were prepared by the screen printing method. They were sintered at 870, 880, 890 and 900℃, and then their physical and magnetic properties were analyzed. After sintering at 870℃, the sintered density of the ferrite sheet doped with 0.5wt% V₂O/sub 5/ showed the highest value to 5.08g/cm³due to the best densification by the liquid phase sintering, while the microstructures of ferrite sheets doped with 0.1 and 0.3 wt% V₂O/sub 5/ showed and inhibited grain growth. Irrespective of the sintering temperature, the initial permeability of ferrite sheet doped with 0.5 wt% V₂O/sub 5/ was highest and after sintering beyond 880℃, the quality factor of 0.3 wt% V₂O/sub 5/-doped sample appeared to be highest.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.70-76
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• 2014

$Zn_2TiO_4$, using an anatase form of $TiO_2$ on zinc crystalline glaze, was shown as effective nuclear agent. Thus the effects on glaze were studied with synthesized $Zn_2TiO_4$ at low temperature. First, the chromophore elements were employed in synthesized $Zn_2TiO_4$ then add them in the zinc crystalline glaze. Crystal creation and development of color by $Zn_2TiO_4$ addition on the zinc crystalline glaze were more effective. Addition of $Zn_2TiO_4$, which is developed in low range temperature, is effected as zinc crystalline nuclear in the willemite glaze. When 5 wt% of synthesized $Zn_2TiO_4$ was added to the willemite glaze, nuclear creation increases and steadily retains. Therefore addition of respectively doped $Zn_2TiO_4$ with CoO, NiO, and CuO would increase doped effects in the glaze, various color willemite crystal were obtained.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.313-320
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• 1995

We investigated the preferred orientation, electrical and magnetic properties of the Mn-Zn ferrite thin films deposited on SiO2/Si(100) by ion beam sputtering. The Cu-added Mn-Zn ferrite thin films had a preferred orientation of (111) with a weak orientation, (311). While the Zn-added one had a strong (111) preferred orientation. The saturation magnetization of the Cu- or Zn-doped Mn-Zn ferrite films increased with increasing substrate temperature (Ts) due to the increase of grain size and the enhancement of crystallinity. For the same reason the coercivity of Cu- or Zn-doped Mn-Zn ferrite films deposited at low Ts increased with increasing Ts, but those of the films deposited at high Ts slightly decreased not only because the defect density of the films decreases but because more grains have multi-domains with increasing Ts. The resistivity of Cu- or Zn-added Mn-Zn ferrite thin fims measured by complex impedance method decreased with increasing Ts due to the ehhancement of crystallinity as well as due to the increase of grain size.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.256-256
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• 2010

투명전극부터 디스플레이 산업에 이르기까지 광범위하게 응용되어지고 있고 개발되어지고 있는 투명전도산화물(TCO)은 ZnO, In2O3, SnO2 등을 기본으로 하는 n-type 재료가 대부분이다. 그러나 투명전도 산화물을 이용한 light emitting diode(LED), 투명한 태양전지, p-형 TFT와 같은 투명전자소자의 개발을 위해서는 p-type 소재가 필수적이다. p-type TCO 소재는 비교적 연구 개발 실적이 매우 부진한 실정이었다. 1997년 넓은 밴드갭을 가지는 ABO2(delafossite) 산화물이 p-type으로서 안정적이라는 것을 보고함에 따라 이에 대한 연구가 활발히 진행되고 있다. 현재 ABO2 형태를 가진 Delafossite구조 산화물이 가장 유망한 p-type 투명전도체 소재로 거론되고 있다. Delafossite 구조가 p-type 투명전도체에 적합한 결정구조인 이유는 밴드갭이 넓고 공유결합에 유리하기 때문이다. Delafossite구조는 상온에서 2종류의 polytype(상온에서 Rhombohedaral구조와 hexagonal 구조)이 존재하며 이들은 각각 3R 및 2H의 결정 구조를 가지고 있다. ABO2의 delafossite구조에서 Cu+의 배열은 c-축을 따라 Cu-O-Cr-O-Cu의 연속적인 층 구조로서 2차원연결로 보여 진다. 보고된 Cu- base delafossite구조를 가지는 재료들은 CuAlO2, CuGaO2, CuInO2 등 여러가지가 있다. 본 연구에서는 PLD를 이용하여 c-plane 사파이어 기판위에 성장된 delafossite구조인 CuCrO2박막의 특성을 알아보았다. p-type 특성을 위하여 CuCrO2에 Zn를 첨가하였으며 그에 따른 구조적 전기적 특성을 조사하였다. 성장온도와 산소분압을 $500{\sim}700^{\circ}C$, 0~10mTorr로 변화시켜 특성을 연구하였다. 성장온도 $700^{\circ}C$, 산소분압 10mTorr에서 c-plane 사파이어 기판위에 c-축 배향의 에피성장된 CuCrO2:Zn 박막을 얻을 수 있었다. Mg를 도핑함에 따른 p-type 특성보다 현저히 떨어지는 것을 확인하였다. 또한 동일한 조건임에도 특정한 이차상의 존재를 통해 도핑된 Zn의 위치를 추측할 수 있었다. 온도와 분압에 따른 결정성과 표면상태를 SEM을 통해서 확인하였다.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.44-48
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• 2017

We explain optical and electrical properties of top and bottom-emission structured alternating-current powder electroluminescent devices (ACPELDs) with Ga-doped ZnO(GZO) transparent electrode. The top-emission ACPELDs were layered as the metal electrode/dielectric layer/emission layer/top transparent electrode and the bottom-emission ACPELDs were structured as the bottom transparent electrode/emission layer/dielectric layer/metal electrode. The yellow-emitting ZnS:Mn, Cu phosphor and the barium titanate dielectric layers were layered through the screen printing method. The GZO transparent electrode was deposited by the sputtering, its sheet resistivity is $275{\Omega}/{\Box}$. The transparency at the yellow EL peak was 98 % for GZO. Regardless of EL structures, EL spectra of ACPELDs were exponentially increased with increasing voltages and they were linearly increased with increasing frequencies. It suggests that the EL mechanism was attributed to the impact ionization by charges injected from the interface between emitting phosphor layer and the transparent electrode. The top-emission structure obtained higher EL intensity than the bottom-structure. In addition, charge densities for sinusoidal applied voltages were measured through Sawyer-Tower method.

• Current Photovoltaic Research
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• v.3 no.1
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• pp.32-38
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• 2015

CIGS solar cell consisted of various films. In this research, we investigated electrode materials in $Cu(In,Ga)Se_2$ (CIGS) cells, including Al-doped ZnO (ZnO:Al), intrinsic ZnO (i-ZnO), and Al films. The sputtered ZnO:Al film with a sputtering power at 200W showed the lowest series resistance and highest cell efficiency. The electrical resistivity of the 200-W sputtered ZnO:Al film was $5.2{\times}10^{-4}{\Omega}{\cdot}cm$ by the rapid thermal annealing at $200^{\circ}C$ for 1 min. The electrical resistivity of i-ZnO was not measurable due to its high resistance. But the optical transmittance was highest with less oxygen supply and high efficiency cell was achieved with $O_2/(Ar+O_2)$ ratio was 1% due to the increase of short-circuit current. No significant change in the cell performance by inserting a Ni layer between Al and ZnO:Al films was observed.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1999.06a
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• pp.371-387
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• 1999

La2-xSrxCuO4 single-crystalline films were prepared on bulk single crystals of Zn-doped La2CuO4 as the substrates by LPE technique using tow deferent methods. When prepared using an alumina crucible in normal electrical furnace, the La2-xSrxCuO4 films were contaminated with less than 3 at% aluminum from the alumina crucibles. Aluminum contamination either reduced or completely destroyed the superconductivity of the La2-xSrxCuO4 films. For LPE growthby modified TSFZ method using an infrared heating furnace without crucibles, the La2-xSrxCuO4 films of x=0.11 showed superconducting with Tconset 36 K, which is 10 K higher than that in the La2-xSrxCuO4 bulk single crystals.