• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.336-336
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• 2010

Ga doped ZnO (GZO) transparent conductive films were deposited on the glass substrates at room temperature by facing target sputtering (FTS) method. The sputtering targets were 100 mm diameter disks of GZO($Ga_2O_3$ 3.w.t%) and Zn metal. The GZO thin films were deposited as a various $PO_2$ (oxygen gas content). Base pressure was $2{\times}10^{-6}$torr, and a working pressure was 1mTorr. The properties of thin films on the electrical and optical properties of the deposited films were investigated by using a four-point probe, a Hall Effect measurement and an UV/VIS spectrometer. The minimum resistivity of film was $6.5{\times}10^{-4}$[$\Omega$-cm] and the average transmittance of over 80% was seen in the visible range.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1035-1039
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• 1999

Manganese-activated zincgallate (Zn1-xMnxGa2O4) phosphor as a green phosphor was readily prepared by coprecipitation in aqueous basic solution of metal salts. The obtained product converted to amorphous zincgallate even at 300℃, followed by crystallization at 1000 ℃. The pyrolyzed phosphor showed fine particle, then reduction treatment at 900 ℃ changed into homogeneous shape with slight grain growth(particle size less than 0.5 mm). The photoluminescence characteristics of the zincgallates have been investigated as a function of dopant concentrations, reducing atmospheres and temperatures. Under UV excitation the phosphors displayed the highest green emission efficiency at 504 nm when the specimen oxidized at 1000 ℃ was reduced at 900 ℃ in a mild hydrogen atmosphere (97% N2, 3% H2) with a flow rate of 100 ml/min.

• 한국세라믹학회지
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• 제48권4호
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• pp.328-333
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• 2011

The influence of Al-doped ZnO (AZO) thin films degraded under high temperature and damp heat on the performance deterioration of Cu(In,Ga)$Se_2$ (CIGS) solar cells was investigated. CIGS solar cells with AZO/CdS/CIGS/Mo structure were prepared on glass substrate and exposed to high temperature ($85^{\circ}C$) and damp heat ($85^{\circ}C$/85% RH) for 1000 h. As-prepared CIGS solar cells had 64.91% in fill factor (FF) and 12.04% in conversion efficiency. After exposed to high temperature, CIGS solar cell had 59.14% in FF and 9.78% in efficiency, while after exposed to damp heat, it had 54.00% in FF and 8.78% in efficiency. AZO thin films in the deteriorated CIGS solar cells showed increases in resistivity up to 3.1 times and 4.4 times compared to their initial resistivity after 1000 h of high temperature and damp heat exposure, respectively. These results can be explained by the decreases in carrier concentration and mobility due to diffusion or adsorption of oxygen and moisture in AZO thin films. It can be inferred that decreases in FF and conversion efficiency were caused by an increase in series resistance, which resulted from an increase in resistivity of AZO thin films degraded under high temperature and damp heat.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.1-5
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• 2016

The ultimate aims of display market is transparent or flexible. Researches have been carried out for various applications. It has been possible to reduced the process steps and get good electrical properties for semiconductors with large optical bandgaps. Oxide semiconductors have been established as one of the leading and promising technology for next generation display panels. In this paper, alternative treatment processes have been tried for oxide semiconductors of thin film transistors to increase the electrical properties of the thin film transistors and to investigate the mechanisms. There exist a various oxide semiconductors. Here, we focused on InGaZnO, ZnO and InSnZnO which are commercialized or researched actively.

• 한국재료학회지
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• 제26권6호
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• pp.347-352
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• 2016

ZnO with wurtzite structure has a wide band gap of 3.37 eV. Because ZnO has a direct band gap and a large exciton binding energy, it has higher optical efficiency and thermal stability than the GaN material of blue light emitting devices. To fabricate ZnO devices with optical and thermal advantages, n-type and p-type doping are needed. Many research groups have devoted themselves to fabricating stable p-type ZnO. In this study, $As^+$ ion was implanted using an ion implanter to fabricate p-type ZnO. After the ion implant, rapid thermal annealing (RTA) was conducted to activate the arsenic dopants. First, the structural and optical properties of the ZnO thin films were investigated for as-grown, as-implanted, and annealed ZnO using FE-SEM, XRD, and PL, respectively. Then, the structural, optical, and electrical properties of the ZnO thin films, depending on the As ion dose variation and the RTA temperatures, were analyzed using the same methods. In our experiment, p-type ZnO thin films with a hole concentration of $1.263{\times}10^{18}cm^{-3}$ were obtained when the dose of $5{\times}10^{14}$ As $ions/cm^2$ was implanted and the RTA was conducted at $850^{\circ}C$ for 1 min.

• Transactions on Electrical and Electronic Materials
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• 제15권4호
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• pp.198-200
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• 2014

100 nm thick Ga doped ZnO (GZO) thin films were deposited with RF magnetron sputtering on polyethylene terephthalate (PET) and ZnO coated PET substrate and then the effect of the ZnO thickness on the optical and electrical properties of the GZO films was investigated. GZO single layer films had an optical transmittance of 83.7% in the visible wavelength region and a sheet resistance of $2.41{\Omega}/{\square}$, while the optical and electrical properties of the GZO/ZnO bi-layered films were influenced by the thickness of the ZnO buffer layer. GZO films with a 20 nm thick ZnO buffer layer showed a lower sheet resistance of $1.45{\Omega}/{\square}$ and an optical transmittance of 85.9%. As the thickness of ZnO buffer layer in GZO/ZnO bi-layered films increased, both the conductivity and optical transmittance in the visible wavelength region were increased. Based on the figure of merit (FOM), it can be concluded that the ZnO buffer layer effectively increases the optical and electrical performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.204.1-204.1
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• 2013

Fluorine, the radius of which is close to that of oxygen, could be an appropriate anion doping candidate. A lower lattice distortion could be expected for F doping, compared with Al, Ga, and In doping. F-doped ZnO (FZO) and undoped ZnO nanorods were grown onto glass substrate by the hydrothemal method. The doping level in the solution, designated by F/Zn atomic ratio of was varied from 0.0 to 10.0 in 2.0 steps. To investigate the effects of the structure and optical properties of FZO nanorods were investigated using X-ray diffraction, UV-visible spectroscopy and photoluminescence (PL). For the PL spectra, the maximum peak position of NBE moves to higher energy, from 0 to 4 at.%. As the doping concentration increases, the maximum peak position of NBE gradually moves to lover energy, from 4 to 10 at.%.

• 한국세라믹학회지
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• 제39권10호
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• pp.935-942
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• 2002

Ga 첨가된 ZnO(GZO) 박막을 5.7 wt%의 $Ga_2O_3$를 ZnO에 첨가된 세라믹 GZO 타켓을 사용하여 직류 마그넷 스퍼터에 의해 실온의 유리 기판위에 제작했다. 각각 질량이 서로 다른 Ne, Ar, Kr 가스의 다양한 전압(total gas pressure)에서 제작한 GZO 박막에 대하여, 타켓의 에로젼 영역(B영역)과 비에로젼 영역(A영역)에 대향하는 박막 영역의 전기적 특성을 조사했다. 가스 종류와 관계없이 B 영역의 대향부분은 비에로젼 영역과 비교해서, 홀 이동도와 캐리어 밀도의 감소에 의해 상대적으로 높은 비저항값을 보였다. Ne 가스를 사용한 경우, GZO 박막은 가장 높은 비저항값을 나타낸 반면, Kr 가스를 사용하여 제작한 GZO 박막은 상대적으로 가장 낮은 비저항값을 보였다. GZO 박막의 전기적 특성은 박막의 결정성에 크게 의존하고 있음을 알았으며 박막의 전기적 특성과 결정성의 저하를 일으키는 인자로서 성장중의 박막의 결정성에 크게 의존하고 있음을 알았으며 박막의 전기적 특성과 결정성의 저하를 일으키는 인자로서 성장중의 박막표면에 충돌하여 박막에 손상을 입히는 고에너지 입자를 들 수 있다. Ne, Ar, Kr 가스의 반사 중성 원자들의 에너지를 Monete Carlo simulation에 의한 계산한 결과는 실험 결과와 잘 일치함을 알 수 있었다.

• 열처리공학회지
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• 제27권1호
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• pp.23-26
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• 2014

Ga doped ZnO (GZO) single layer and GZO/ZnO bi-layered films were deposited on glass substrates by radio frequency magnetron sputtering and then the influence of film thickness on the structural, electrical, and optical properties of the films was considered. Thicknesses of the GZO/ZnO films was varied as GZO 100 nm, GZO 85 nm/ZnO 15 nm and GZO 70 nm/ZnO 30 nm, respectively. The observed result means that optical transmittance and electrical resistivity of the films were influenced with film thickness and GZO 85 nm/ZnO 15 nm bilayered films show the higher figure of merit than that of the films prepared other films in this study.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.336.2-336.2
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• 2014

Indium Tin Oxide (ITO) thin films are used as the Transparent Conducting Oxide (TCO), such as flat panel display, transparent electrodes, solar cell, touch screen, and various optical devices. ZnO has attracted attention as alternative materials to ITO film due to its resource availability, low cost, and good transmittance at the visible region. Recently, very thin film deposition is important. In order to minimize the damage caused by bending. However, ZnO thin film such as Ga-doped ZnO(GZO) has poor sheet resistance characteristics. To solve this problem, By adding the conductive metal on films can decrease the sheet resistance and increase the mobility of the films. In this study, We analyzed the electrical and optical characteristics of GZO/Ag/GZO (GAG) films by change in Ag and GZO thickness.