• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.87.1-87.1
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• 2012

넓은 밴드갭 (3.37eV)과 높은 엑시톤 결합에너지 (60meV)를 가지는 ZnO 물질은 ultra violet light 센서 및 light emitting diode (LED)의 재료로써 많은 연구가 진행되고 있다. 특히 나노와이어 구조를 이용하여 소자를 만들 경우 양자효과와 1차원적 캐리어 수송경로 효과로 인하여 그 특성을 보다 향상 시킬 수 있다. 나노와이어를 이용한 이종접합 p-n 다이오드를 제작하기 위하여 ZnO와 격자상수가 비슷한 GaN, NiO, CoO와 같은 물질들이 나노구조 접합에 많이 쓰이고 있지만, 격자상수 차이로 인해서 접합부분 캐리어 수송효율이 떨어지는 단점을 가지고 있다. n-type과 p-type ZnO를 만들어 동종 접합을 만들 경우 이러한 문제점을 극복할 수 있지만, 도핑되지 않은 ZnO가 n-type을 특성을 나타내기 때문에 안정적인 p-type ZnO 합성에 대한 연구가 필수적이다. 본 연구에서는 안정적인 p-type ZnO 합성을 위해서 수열합성법을 이용하여 phosphorus (P) 도핑을 하였고, 나노와이어 diode 구조를 만들었다. P 도핑으로 인한 격자상수 변화는 x-ray diffraction (XRD)를 사용하여 확인하였고, x-ray photoelectron spectroscopy (XPS)를 통해 도핑 원소를 분석하였으며, 이때의 recification ratio, turn-on voltage 등의 전기적 특성을 평가하였다.

• 한국재료학회지
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• 제26권4호
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• pp.222-227
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• 2016

Tin oxides have been studied for various applications such as gas detecting materials, transparent electrodes, transparent devices, and solar cells. p-type SnO is a promising transparent oxide semiconductor because of its high optical transparency and excellent electrical properties. In this study, we fabricated p-type SnO thin film using rf magnetron sputtering with an SnO/Sn composite target; we examined the effects of various oxygen flow rates on the SnO thin films. We fundamentally investigated the structural, optical, and electrical properties of the p-type SnO thin films utilizing X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV/Vis spectrometry, and Hall Effect measurement. A p-type SnO thin film of $P_{O2}=3%$ was obtained with > 80% transmittance, carrier concentration of $1.12{\times}10^{18}cm^{-3}$, and mobility of $1.18cm^2V^{-1}s^{-1}$. With increasing of the oxygen partial pressure, electrical conductivity transition from p-type to n-type was observed in the SnO crystal structure.

• Journal of the Korean Physical Society
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• 제81권
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• pp.867-875
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• 2022

This paper explored the effect of deposition conditions on the characteristics of copper oxide (CuO_x) thin films prepared by direct current (DC) magnetron sputtering. X-ray diffraction exhibited that CuO with n-type conductivity was the main composition regardless of the DC magnetron sputtering power whereas the phase transition from n-type CuO to p-type Cu₂O was observed with decreasing the oxygen pressure (OP) from 40 to 20%. The optical band gap ranges of 1.6-1.9 eV, which are characteristic of n-type CuO, were determined for samples prepared with OPs of 30-40% while the optical band gap of 2.3 eV, which is characteristic of p-type Cu₂O, was measured for samples prepared with an OP of 20%. In addition, only Cu⁺ X-ray photoelectron spectroscopy (XPS) peak at the ~932.6 eV position exists in the films deposited with an OP of 20%, whereas only Cu²⁺ XPS peaks at ~934.2 eV and in the range of 940-945 eV are observed in the films deposited with an OP of 40%. Furthermore, as a result of XPS depth profile analysis, it was confirmed that the composition ratio of the sample prepared at an OP of 20% was Cu₂O, whereas the composition ratio of the sample prepared at an OP of 40% was CuO. These suggest that the CuO_x thin films could be constantly converted from n-type CuO to p-type Cu₂O by decreasing the oxygen partial pressure. Thin film transistors with Cu₂O deposited at 20% OP revealed p-type characteristics such as onset voltage (V_ON) of -3 V, saturated hole mobility of 8 cm²/Vs at V_GS = -28 V, subthreshold swing of 0.86 V/decade at V_GS-V_ON = -0.5 V, and on/off ratio of 1.14 × 10³.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.143-143
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• 2010

In this study, we demonstrate that ZnO deposited onto $SiO_2$ substrates by magnetron sputtering produces p-type ZnO at higher $O_2$ pressure and n-type ZnO at lower $O_2$ pressure. We also report the effect of hydrogen peroxide ($H_2O_2$) on the stability of undoped ZnO thin films. The films were immersed in 30% $H_2O_2$ for 1 min at $30^{\circ}C$ and annealed in $O_2$at $450^{\circ}C$. The carrier concentration, mobility. and conductivity were measured by a Hall effect measurement system. The Hall measurement results for ZnO films untreated with $H_2O_2$ but annealed in $O_2$ indicate that oxygen fraction greater than ~0.5 produces undoped p-type ZnO films, whereas oxygen fraction less than ~0.5 produces undoped n-type ZnO films. This is attributed to the fact that the oxygen vacancies ($V_o$) decrease and the oxygen interstitials ($O_i$) or zinc vacancies ($V_{Zn}$) increase with increasing oxygen atoms incorporated into ZnO films during deposition and $O_2$ post-annealing.

• Transactions on Electrical and Electronic Materials
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• 제9권1호
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• pp.24-27
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• 2008

ZnO has intensively attracted interest for the next generation of short wavelength LEDs and semiconductor lasers. However, for the development and application of the devices based on this material, the fabrication of p-type ZnO thin films is pivotal. Generally, the process of preparation of ZnO is unavoidably accompanied by the natural donor ions such as interstitial Zn ions and oxygen vacancy ions that show n-type electrical property and make fabrication of p-type ZnO to be a hard problem. On this study, to realize stable high-quality p-type ZnO thin films, the undoped ZnO thin films were diffused with P in vapor state. The ZnO:P thin films showed high-quality p-type properties electrically and optically.

• 한국콘텐츠학회논문지
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• 제21권7호
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• pp.340-350
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• 2021

본 연구는 소비자의 레스토랑O2O 서비스의 운영 행태에 대하여 심층적이고 본질 적인 의미에 접근할 수 있는 질적 분석방법의 하나가 되는 Q연구방법을 활용하며 연구하였다. 연구의 목적은 레스토랑O2O 서비스의 행태에 대하여 유형별로 분류하여 변수 간의 특성을 알며, 향후 방향을 개선하며 제시 하는데 있다. 레스토랑 O2O 서비스의 행태에 관한 주관적 인식을 분석하려고 Q-방법론을 이용하여 탐색적인 연구를 진행하였다. 이를 위해 긍정과 부정의 진술문 카드를 작성하여 P샘플을 선정하고 분류작업을 거치는 Q-sort를 PC QUANL프로그램을 이용하고 Q요인 분석을 실시하였다. 분석결과 3가지의 단일 유형으로 분류되었고, 제 1유형【(N= 7: 레스토랑O2O서비스 편익증후군형】, 제 2유형【(N= 7): 레스토랑O2O서비스 편익추구형】, 제 3유형【(N= 6): 레스토랑O2O서비스 편익효율형】으로 요인 명을 설정하였다. 각 유형마다 서로 특징이 다른 것으로 나타났다. 또한 분석을 통하여 검출된 각각 요인에 따른 마케팅 전략을 제시하고 레스토랑 O2O서비스의 보완점과 추후 운영 방향을 제시하고자 한다.

• 한국양식학회지
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• 제8권1호
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• pp.59-67
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• 1995

해산어류 종묘생산시 초기단계 먹이생물로서 많이 이용되고 있는 rotifer, Brachionus plicatilis의 large (L)-type, small (S)-type, thailand small (TS)-type에 대한 수온과 염분별 성장율, 최초산란 연령, 수명 및 총산란수 등에 관해 조사한 결과는 다음과 같다. 각 염분%$(5\%o,\;15\%o,\;25\%o,\;and\;35\%o)$에 따른 개체군 성장은 L-type은 $25^{\circ}C\;와\;29^{\circ}C$에서 비교적 양호한 성장을 보였으며 평균성장율은 $0.53\~0.71$이었고, S-type과 TS-type은 $29^{\circ}C$에서 각각 $0.81\~0.87,\;0.92\~1.04$였다. 최초산란연령은 3 type 모두 저염분, 고수온조건에서 빨랐으며 L-type은 $15\%o$구, $29^{\circ}C$에서 22.7시간, S-type은 $15\%o$구, $29^{\circ}C$에서 18시간, TS-type은 $5\%o$구, $29^{\circ}C$에서 18.8시간이었다. 총산란수는 3 type 모두 $25^{\circ}C$와 $29^{\circ}C$ 조건하에서 다산하였고, TS-type에 있어 $29^{\circ}C$에서 평균 28.3개체로 최대치를 나타냈고, S-type은 $15^{\circ}C$에서 평균 7.8개체로 가장 낮은 산란수를 나타냈다. 수명은 고수온에서는 짧고, 저수온에서는 길었으며 L-type과 TS-type에 있어 $15^{\circ}C$에서 평균 13.5일로 가장 길었고, S-type은 $29^{\circ}C$에서 평균 6.2일로 가장 짧았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.55-56
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• 2007

The p-type ZnO thin film, fabricated by means of the ampoule-tube method, was used to make the ZnO p-n junction, and its characteristics was analyzed. The ampoule-tube method was used to make the p-type ZnO based on the As diffusion, and the hall measurement was used to confirm that the p-type is formed. the current-voltage characteristics of the ZnO p-n junction were measured to confirm the rectification characteristics of a typical p-n junction and the low leakage voltage characteristics. Using the ampoule-tube to fabricate the p-type ZnO will provide a very useful technology for producing the UV ZnO LED and ZnO-based devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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• pp.65-66
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• 2008

The realization and origin of p-type ZnO are main issue for photoelectronic devices based on ZnO material. N-doped and nominally undoped p-type ZnO films were achieved on silicon (100) and homo-buffer layers by RF magnetron sputtering and post in-situ annealing. The undoped film shows high hole mobility of 1201 $cm^2V^{-1}s^{-1}$ and low resistivity of $0.0454\Omega{\cdot}cm$ with hole concentration of $1.145\times10^{17}cm^{-3}$. The photoluminescence(PL) spectra show the emissions related to FE, DAP and defects of $V_{Zn}$, $V_O$, $Zn_O$, $O_i$ and $O_{Zn}$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.410-411
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• 2007

To investigate the ZnO LED which are interested in the next generation of short wavelength LEDs and Lasers, the ZnO thin films were deposited by RF magnetron sputtering system. The p-type ZnO thin film, fabricated by means of the ampoule-tube method, was used to make the ZnO p-n junction, and its characteristics was analyzed. The ampoule-tube method was used to make the p-type ZnO based on the As diffusion, and the hall measurement was used to confirm that the p-type is formed. the current-voltage characteristics of the ZnO p-n junction were measured to confirm the rectification characteristics of a typical p-n junction and the low leakage voltage characteristics. Analysis of ZnO LED V-I curve will provide a very useful technology for producing the UV ZnO LED and ZnO-based devices.