• Korean Journal of Materials Research
• /
• v.24 no.10
• /
• pp.543-549
• /
• 2014

A zinc oxide (ZnO) hybrid structure was successfully fabricated on a glass substrate by metal organic chemical vapor deposition (MOCVD). In-situ growth of a multi-dimensional ZnO hybrid structure was achieved by adjusting the growth temperature to determine the morphologies of either film or nanorods without any catalysts such as Au, Cu, Co, or Sn. The ZnO hybrid structure was composed of one-dimensional (1D) nanorods grown continuously on the two-dimensional (2D) ZnO film. The ZnO film of 2D mode was grown at a relatively low temperature, whereas the ZnO nanorods of 1D mode were grown at a higher temperature. The change of the morphologies of these materials led to improvements of the electrical and optical properties. The ZnO hybrid structure was characterized using various analytical tools. Scanning electron microscopy (SEM) was used to determine the surface morphology of the nanorods, which had grown well on the thin film. The structural characteristics of the polycrystalline ZnO hybrid grown on amorphous glass substrate were investigated by X-ray diffraction (XRD). Hall-effect measurement and a four-point probe were used to characterize the electrical properties. The hybrid structure was shown to be very effective at improving the electrical and the optical properties, decreasing the sheet resistance and the reflectance, and increasing the transmittance via refractive index (RI) engineering. The ZnO hybrid structure grown by MOCVD is very promising for opto-electronic devices as Photoconductive UV Detectors, anti-reflection coatings (ARC), and transparent conductive oxides (TCO).

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.55.1-55.1
• /
• 2010

차세대 디스플레이용 전극 재료는 투명하면서도 낮은 저항값을 가져야 하는 투명 전극 재료로 금속, 금속산화물, 전도성 고분자, 탄소재료 등을 들 수 있다. 금속재료는 전도도는 우수하지만, 낮은 투과도로 투명전극 재료로 적절하지 않고, 대표적인 금속산화물 재료인 indium tin oxide (ITO)의 경우, 우수한 투과성과 낮은 면저항을 기반으로 차세대 디스플레이용 전극으로 현재 사용되고 있다. 하지만 ITO 박막은 휘거나 접을 때 기계적 안정성이 취약한 문제점을 나타내고 있다. 이러한 문제점을 극복하기 위해 전도성과 탄성계수가 높고, 저온에서 대면적 공정이 가능한 CNT을 투명 박막 전극 연구가 활발히 진행되고 있다. 하지만 투명전극 제조시, 탄소 나노튜브 간의 van der waals 인력에 의한 응집 현상으로 인한 분산의 불안정성과 분산제 사용으로 인하여 탄소 나노튜브 박막전극의 전기적, 광학적 특성이 저하를 야기한다. 이에 본 실험에서는 아크 방전 공정으로 합성한 SWCNT 분산액을 사용하여 spray coating 방법으로 glass 위에 박막을 형성하였다. SWCNT 투명 박막 전극 위에 DC sputtering을 이용하여 얇은Ni를 도포한 후, $450{\sim}500^{\circ}C$, ethylene gas 분위기의 thermal CVD방법으로 Carbon NanoFibers (CNFs)를 생성시킴과 동시에 분산제를 burning out하였다. CNF 성장 전후의 투명 박막의 전기적 특성은 four point probe를 이용하여 면저항과 UV-vis 장비를 이용하여 가시광선 영역에서의 광학적 투과도를 측정 비교하였다.

• Journal of Surface Science and Engineering
• /
• v.52 no.3
• /
• pp.145-149
• /
• 2019

Transparent and conductive ZnO/Ag/SnO2 (ZAS) tri-layer films were deposited onto glass substrates at room temperature by using radio frequency (RF) and direct current (DC) magnetron sputtering. The thickness values of the ZnO and $SnO_2$ thin films were kept constant at 50 nm and the value for Ag interlayer was varied as 5, 10, 15, and 20 nm. In the XRD pattern the diffraction peaks were identified as the (002) and (103) planes of ZnO, while the (111), (200), (220), and (311) planes could be attributed to the Ag interlayer. The optical transmittance and electrical resistivity were dependent on the thickness of the Ag interlayer. The ZAS films with a 10 nm thick Ag interlayer exhibited a higher figure of merit than the other ZAS films prepared in this study. From the observed results, a ZAS film with a 10 nm thick Ag interlayer was believed to be an alternative transparent electrode candidate for various opto-electrical devices.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.127.2-127.2
• /
• 2011

본 연구에서는 RF Magnetron Sputtering System을 이용하여 ZnO계 투명전도막 증착시 Vaporization된 MeOH를 유입함으로써 박막증착과 동시에 표면의 Roughness를 제어하여 이에따른 전기적 특성 및 광학적 특성의 개선에 대하여 연구하였다. 실험방법으로 기존의 RF Magnetron Sputtering System에 Vaporization이 가능한 Ultrasonic을 이용하여 MeOH를 Vaporized시켜 MFC Controll을 통해 챔버에 유입하여 ZnO계 투명전도막의 박막증착과 동시에 표면 Texturing을 하였다. ZnO계 투명전도막의 박막증착시 Vaporized MeOH의 유입에 따른 광학적 특성변화를 UV-visible-nIR spectrometry로 조사하였으며, 전기적 특성 변화를 4-Point-Probe로 조사하였으며, 표면적 특성 변화를 Atomic Force Microscope(AFM), Scanning Electron Microscopy(SEM)를 조사하였으며, 박막의 결정성장특성 변화를 X-ray Diffraction(XRD)으로 조사하였으며, Vaporized MeOH 유입에 따른 박막의 성분분석을 Secondary Ion Mass Spectrometry (SIMS)로 조사함으로써 최적의 조건 및 공정을 확립하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1535-1537
• /
• 2009

High performance resistive type touch panel was fabricated on flexible polyethylene terephthalate (PET) substrates coated with Al- and Ga-codoped ZnO (AGZO) films. The AGZO films were deposited by roll-to-roll direct current magnetron sputter at room temperature. The AGZO thin films on PET substrates showed high transparency (> 85 % at 550 nm) and low sheet resistance (450 ${\Omega}$/sq.). These values were similar to those of commercial ITO films used for resistive type touch panel.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.446-447
• /
• 2007

Aluminisum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). In our paper, AZO films have been deposited on glass (coming 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$, $800^{\circ}C$ for 2 hr with $N_2$ atmosphere, respectively. We investigated that the electric properties and qualitative analysis of AZO films, which measured using the methods of Hall effect, X-ray photoelectron spectroscopy (XPS).

• Korean Journal of Materials Research
• /
• v.31 no.6
• /
• pp.320-324
• /
• 2021

Effects of growth variables and post-growth annealing on the optical, structural and electrical properties of magnetron-sputtered Ga_0.04Mg_0.10Zn_0.86O films are characterized in detail. It is observed that films grown from pure oxygen plasma showed high resistivity, ~10² Ω·cm, whereas films grown in Ar plasma showed much lower resistivity, 2.0 × 10^-2 ~ 1.0 × 10^-1 Ω·cm. Post-growth annealing significantly improved the electrical resistivity, to 4.3 ~ 9.0 × 10^-3 Ω·cm for the vacuum annealed samples and to 1.3 ~ 3.0 × 10^-3 Ω·cm for the films annealed in Zn vapor. It is proposed that these phenomena may be attributed to the improved crystalline quality and to changes in the defect chemistry. It is suggested that growth within oxygen environments leads to suppression of oxygen vacancy (Vo) donors and formation of Zn vacancy (V_Zn) acceptors, resulting in highly resistive films. After annealing treatment, the activation of Ga donors is enhanced, Vo donors are annihilated, and crystalline quality is improved, increasing the electron mobility and the concentration. After annealing in Zn vapor, Zn interstitial donors are introduced, further increasing the electron concentration.

• Journal of Surface Science and Engineering
• /
• v.38 no.4
• /
• pp.150-155
• /
• 2005

Highly conductive and transparent in the visible region tin-doped indium oxide(ITO) thin films were deposited on Corning glass by r.f sputtering. To achieve high transmittance and low resistivity, we examined various parameters such as r.f power and deposition time. The films crystallinity shifted from (222) to (400) and (440) orientation as deposition time and r.f power increased. Surface roughness RMS value increased proportionally with deposition time. The lowest resistivity was $5.36{\times}10^{-4}{\Omega}{\cdot}cm$ at 750 nm thickness, $200^{\circ}C$ substrate temperature and 125 w r.f power. All of the films showed over $85\%$ transmittance in the visible wavelength range.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.4
• /
• pp.217-220
• /
• 2017

We deposited transparent conductive ZTO/Ag/ZTO trilayer thin films on glass substrates through magnetron sputtering, and then conducted intense electron beam irradiation on their surfaces to investigate the effects of electron irradiation on the structural, optical, and electrical properties of these films. After deposition, we electron irradiated the ZTO/Ag/ZTO films for 10 min at electron energies of 300, 500, and 700 eV. The films that were electron irradiated at 700 eV showed a higher optical transmittance (84.2%) in the visible wavelength region and a lower resistivity ($7.2{\times}10^{-5}{\Omega}cm$) compared with the other films. The figure of merit revealed that the ZTO/Ag/ZTO films that were electron irradiated at 700 eV had a higher optical and electrical performance than the other films prepared in this study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.2
• /
• pp.169-174
• /
• 2024

In this study, the structural, electrical, and optical properties of AZO films of various thicknesses are compared. The AZO films were deposited on a glass substrate by FTS (Facing-Target-Sputtering) This research was conducted to find the optimal thickness for Transparent Conductive Oxide (TCO). AZO has suitable properties for TCO such as low resistivity, and high transmittance. Thin films of all thicknesses showed a transmittance of over 80% in the visible light region and electrical properties improved as thickness increased. It was confirmed that the film of 300 nm thick had the best performance due to its low resistivity, and uniform surface. This research is expected to help find optimal conditions in various fields where TCO is used, such as solar cells, displays, and sensors in the future.