• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.175-175
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• 2010

Transparent conducting oxide (TCO) films are widely used as transparent conducting thin film material for application in various fields such as solar cells, optoelectronic devices, heat mirrors and gas sensors, etc. Recently the increased utilization of many transparent electrodes has accelerated the development of inexpensive TCO materials. Indium tin oxide (ITO) film is well-known for TCO materials because of its low resistivity, but there is disadvantage that it is too expensive. ZnO film is cheaper than ITO but it shows thermally poor stability. On the contrary, antimony-doped tin oxide films (ATO) are more stable than TCO films such as Al-doped zinc oxide (AZO) and ITO. Moreover, SnO2 film shows the best thermal and chemical stability, low cost and mechanical durability except the poor conductivity. However, annealing is proved to improve the conductivity of ATO film. Therefore, in this work, antimony (6 wt%) doped tin oxide films to improve the conductivity were deposited on 7059 corning glass by RF magnetron sputtering method for the application to transparent electrodes. In general, of all TCO films, glass is the most commonly selected substrate. However, for future development in flexible devices, glass is limited by its intrinsic inflexibility. In this study, we report the growth and properties of antimony doped tin oxide (ATO) films deposited on PES flexible substrate by using RF magnetron sputtering. The optimization process was performed varying the sputtering parameters, such as RF power and working pressure, and parameter effect on the structural, electrical and optical properties of the ATO films were investigated.

• Korean Journal of Materials Research
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• v.30 no.1
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• pp.1-7
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• 2020

Doping or incorporation with exotic elements are two manners to regulate the optoelectronic properties of transparent conducting (TCO) cadmium oxide (CdO). Nevertheless, the method of doping host CdO by CdTe semiconductor is of high importance. The structural, optical, and electrical properties of CdTe-doped CdO films are studied for the sake of promoting their conducting parameters (CPs), including their conductivity, carrier concentration, and carrier mobility, along with transparency in the NIR spectral region; these are then compared with the influence of doping the host CdO by pure Te ions. X-ray fluorescence (XRF), X-ray diffraction (XRD), optical absorption spectroscopy, and electrical measurements are used to characterise the deposited films prepared by thermal evaporation. Numerous results are presented and discussed in this work; among these results, the optical properties are studied through a merging of concurrent BGN (redshift) and BGW (blue shift) effects as a consequence of doping processes. The impact of hydrogenation on the characterisations of the prepared films is investigated; it has no qualitative effect on the crystalline structure. However, it is found that TCO-CPs are improved by the process of CdTe doping followed by hydrogenation. The utmost TCO-CP improvements are found with host CdO film including ~ 1 %Te, in which the resistivity decreases by ~ 750 %, carrier concentration increases by 355 %, and mobility increases by ~ 90 % due to the increase of N_carr. The improvement of TCO-CPs by hydrogenation is attributed to the creation of O-vacancies because of H₂ molecule dissociation in the presence of Te ions. These results reflect the potential of using semiconductor CdTe -doped CdO thin films in TCO applications. Nevertheless, improvements of the host CdO CPs with CdTe dopant are of a lesser degree compared with the case of doping the host CdO with pure Te ions.

• Current Photovoltaic Research
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• v.3 no.2
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• pp.50-53
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• 2015

Indium (In) is widely used for transparent electrodes of photovoltaics as a form of indium tin oxide (ITO) due to its superior characteristics of environmental stability, relatively low electrical resistivity and high transparency to visible light. However, In has been worn off in proportion to growth the In related market, and it leads to raise of price. Although In is obtained from ITO target scarps, much harmful elements are used for the recycling process. To decrease of harmful elements, ITO swarf particles obtained from target scraps was characterized whether it is feasible to transparent conductive oxide (TCO). The ITO swarf was crushed with milling process, and it was mixed with new ITO nanoparticles. The mixed particles were well dispersed into ink solvent to make-up an ink, and it was well coated onto glass substrate. After heat-treatment at $400^{\circ}C$ under $N_2$ rich environments, optical transmittance at 550 nm and sheet resistance of the ITO ink coated layer was 71.6% and $524.67{\Omega}/{\square}$, respectively. Therefore, it was concluded that the ITO swarf was feasible to TCO of touch screen panel.

• 소프트웨어세계
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• s.4
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• pp.162-169
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• 1999

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.452-452
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• 2013

ZnO is one of the most attractive transparent conductive oxide (TCO) films because of low toxicity, a wide band gap material and relatively low cost. However, the electrical conductivity of un-doped ZnO is too high to use it as TCO films in practical application. To improve electrical properties of undoped ZnO, transition metal (TM) doped ZnO films such as Al doped ZnO or Ti doped ZnO have been extensively studied. Here, we prepared Ti doped ZnO thin films by atomic layer deposition (ALD) for the application of TCO films. ALD was used to prepare Ti-doped ZnO thin films due to its inherent merits such as large area uniformity, precise composition control in multicomponent thin films, and digital thickness controllability. Also, we demonstrated that ALD method can be utilized for fabricating highly ordered freestanding nanostructures of Ti-doped ZnO thin films by combining with BCP templates, which can potentially used in the photovoltaic applications.

• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.236-239
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• 2019

In this work, we performed an optical simulation study on the performance of a PMDPP3T:PCBM based on an organic photovoltaic (PV) device. The virtual PV device was developed in Lumerical, finite-difference time-domain (FDTD) solutions. Different layers of the PV cell have been defined through the incorporation of complex refractive index value of those layers' constituent materials. During the simulation study, the effect of the variation active layer thickness on an ideal short circuit current density ($J_{sc,ideal}$) of the PV cell has been, first, observed. Thereafter, we have investigated the impact of surface roughness of a transparent conducting oxide (TCO) electrode on $J_{sc,ideal}$ of the PV cells. From this simulation, it has been observed that the $J_{sc,ideal}$ value of the PV cell is strongly dependent on the thickness of its active layer and the photon absorption of the PV cell has gradually decreased with the increment of the TCO's surface roughness. As a result, the capability of the PV device has been reduced with the increment of the surface roughness of the TCO.

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

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1125-1128
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• 2007

보안 취약성이 끊임없이 보고되고 있다. 이는 보안솔루션의 초기 효과수준을 유지하기 위해서는, 새로운 취약성이 보고되면 즉시 대처하는 지속적 관리활동이 필요함을 뜻한다. 한편 기업성과 개선을 위한 IT투자성과관리가 강조되는 가운데, 정보보호 솔루션 도입 시 재무적 타당성 증명이 요구되고 있다. 이를 위해 여러 형태의 ROSI(Security ROI)가 제시되었으나, 지속적 보호활동에 따른 관리비용이 중요하게 다루어져야 함에도 불구하고 비용에 대한 고려가 적고 효과산정에만 치우쳐, 경영자의 의사 결정을 지원하는 실제적인 재무 성과지표로 활용될 수 없었다. 이에 본 논문은 조직수준의 비용효과 최적화를 추구하는 정보보호 관리체계에 기반을 두어 효과를 산정하고, 비용 산정은 지속적 관리활동이라는 특징을 반영하여 TCO에 기반을 둔 개선된 ROSI를 제안한다. 또한, 제안한 ROSI를 활용한 보안솔루션 평가사례를 제시한다. 증명이 어려운 정보보호 분야 투자타당성 증명은 물론 보안솔루션 선택 시 실제적인 의사결정 판단근거로서 활용될 수 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.75-75
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• 2011

Recently, dye-sensitized solar cell (DSSC) attracts great attention as a promising alternative to conventional silicon solar cells. One of the key components for the DSSC would be the nanocrystalline TiO2 electrode, and the control of interface between TiO2 and TCO is a highly important issue in improving the photovoltaic conversion efficiency. In this work, we applied various interfacial layers, and analyzed their effect in enhancing photovoltaic properties. In overall, introduction of interfacial layers increased both the Voc and Jsc, since the back-reaction of electrons from TCO to electrolyte could be blocked. First, several metal oxides with different band gaps and positions were employed as interfacial layer. SnO2, TiO2, and ZrO2 nanoparticles in the size of 3-5 nm have been synthesized. Among them, the interfacial layer of SnO2, which has lower flat-band potential than that of TiO2, exhibited the best performance in increasing the photovoltaic efficiency of DSSC. Second, long-range ordered cubic mesoporous TiO2 films, prepared by using triblock copolymer-templated sol-gel method via evaporation-induced self-assembly (EISA) process, were utilized as an interfacial layer. Mesoporous TiO2 films seem to be one of the best interfacial layers, due to their additional effect, improving the adhesion to TCO and showing an anti-reflective effect. Third, we handled the issues related to the optimum thickness of interfacial layers. It was also found that in fabricating DSSC at low temperature, the role of interfacial layer turned out to be a lot more important. The self-assembled interfacial layer fabricated at room temperature leads to the efficient transport of photo-injected electrons from TiO2 to TCO, as well as blocking the back-reaction from TCO to I3-. As a result, fill factor (FF) was remarkably increased, as well as increase in Voc and Jsc.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1528.1-1529
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• 2011

Scribing the transparent conductive oxide(TCO) is an essential technology for the large scaled dye-sensitized solar cell(DSC) and the commercialization of the DSC. Laser systems are most used for scribing technology due to their precision. However, it is difficult to generalize systems because most systems are large and heavy. In this study, we tried to simplificate the Nd:YAG laser system for scribing TCO of the DSC by using switched mode power supply(SMPS) technique. The continuous conduction mode booster converter topology is applied and MC34262 power factor controller is used for the variable frequency control. Finally, SMPS circuit which specifications are 400W of capacity, 400V DC output and 98% of efficiency is fabricated. And it is demonstrated that the scribing TCO is completed by the Nd:YAG laser using this SMPS circuit.