• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2505-2511
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• 2014

Indium oxide nanocrystals ($In_2O_3$ NCs) with sizes of 5.5 nm-10 nm were synthesized by hot injection of the mixture precursors, indium acetate and oleic acid, into alcohol solution (1-octadecanol and 1-octadecence mixture). Field emission transmission electron microscopy (FE-TEM), High resolution X-Ray diffraction (X-ray), Nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FT-IR) were employed to investigate the size, surface molecular structure, and crystallinity of the synthesized $In_2O_3$ NCs. When covered by oleic acid as a capping group, the $In_2O_3$ NCs had a high crystallinity with a cubic structure, demonstrating a narrow size distribution. A high mobility of $2.51cm^2/V{\cdot}s$ and an on/off current ratio of about $1.0{\times}10^3$ were observed with an $In_2O_3$ NCs thin film transistor (TFT) device, where the channel layer of $In_2O_3$ NCs thin films were formed by a solution process of spin coating, cured at a relatively low temperature, $350^{\circ}C$. A size-dependent, non-monotonic trend on electron mobility was distinctly observed: the electron mobility increased from $0.43cm^2/V{\cdot}s$ for NCs with a 5.5 nm diameter to $2.51cm^2/V{\cdot}s$ for NCs with a diameter of 7.1 nm, and then decreased for NCs larger than 7.1 nm. This phenomenon is clearly explained by the combination of a smaller number of hops, a decrease in charging energy, and a decrease in electronic coupling with the increasing NC size, where the crossover diameter is estimated to be 7.1 nm. The decrease in electronic coupling proved to be the decisive factor giving rise to the decrease in the mobility associated with increasing size in the larger NCs above the crossover diameter.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.653-670
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• 2005

The purpose of this study is to explore a spatial agglomeration characteristics and innovative milieu of the shoemaking industry in Seoul. In order to explain it, currently discussed dynamic agglomeration economies approach is applied and as an example, shoemaking industry in Seoul has been analyzed. The result of this research can be boardly summarized into two points. Frist, agglomeration economy is changing from urbanization economy to localization economy in this newly rising core of shoemaking industry which is Sung-Su dong area. Also, cooperative effects based on collective efficiency between companies and people are being generated within the area. This is largely affected by networking infrastructure between companies and people within the area, non-trade dependency and social capital acclamation. Secondly, the lack of institutional agglomeration formation in this area is considered to be the obstacle for the long-term development and innovation spin-off. This means recognition switch-over and institutional concern and support is needed in the future from the public sector.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.347.2-347.2
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• 2014

최근, 비정질 산화물 반도체 thin film transistor (TFT)는 수소화된 비정질 실리콘 TFT와 비교하여 높은 이동도와 큰 on/off 전류비, 낮은 구동 전압을 가짐으로써 빠른 속도가 요구되는 차세대 투명 디스플레이의 TFT로 많은 연구가 진행되고 있다. 한편, 기존의 Thin-Film-Transistor 제작 시 우수한 박막을 얻기 위해서는 $500^{\circ}C$ 이상의 높은 열처리 온도가 필수적이며 이는 유리 기판과 플라스틱 기판에 적용하는 것이 적합하지 않고 높은 온도에서 수 시간 동안 열처리를 수행해야 하므로 공정 시간 및 비용이 증가하게 된다는 단점이 있다. 이러한 점을 극복하기 위해 본 연구에서는 간단하고, 낮은 제조비용과 대면적의 박막 증착이 가능한 용액공정을 통하여 박막 트랜지스터를 제작하였으며 thermal 열처리와 microwave 열처리 방식에 따른 전기적 특성을 비교 및 분석하고 각 열처리 방식의 열처리 온도 및 조건을 최적화하였다. P-type bulk silicon 위에 산화막이 100 nm 형성된 기판에 spin coater을 이용하여 Al-Zn-Sn-O 박막을 형성하였다. 그리고, baking 과정으로 $180^{\circ}C$의 온도에서 10분 동안의 열처리를 실시하였다. 연속해서 Photolithography 공정과 BOE (30:1) 습식 식각 과정을 이용해 활성화 영역을 형성하여 소자를 제작하였다. 제작 된 소자는 Junctionless TFT 구조이며, 프로브 탐침을 증착 된 채널층 표면에 직접 접촉시켜 소스와 드레인 역할을 대체하여 동작시킬 수 있어 전기적 특성을 간단하고 간략화 된 공정과정으로 분석할 수 있는 장점이 있다. 열처리 조건으로는 thermal 열처리의 경우, furnace를 이용하여 $500^{\circ}C$에서 30분 동안 N2 가스 분위기에서 열처리를 실시하였고, microwave 열처리는 microwave 장비를 이용하여 각각 400 W, 600 W, 800 W, 1000 W로 15분 동안 실시하였다. 그 결과, furnace를 이용하여 열처리한 소자와 비교하여 microwave를 통해 열처리한 소자에서 subthreshold swing (SS), threshold voltage (Vth), mobility 등이 비슷한 특성을 내는 것을 확인하였다. 따라서, microwave 열처리 공정은 향후 저온 공정을 요구하는 MOSFET 제작 시의 훌륭한 대안으로 사용 될 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.287-294
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• 2010

The focus of this paper falls on assessing how well rule of crafting government R&D institution spin-off companies(GRSCs), legitimatized to boost up technology commercialization of government research institutions(GRIs) at Daedeok Innopolis in 2006, affect the better business performance of GRSCs, but also delivering alternatives of driving up their better business. First of all, this paper evaluate a management performance of GRSCs at the financial aspect by taking 5 different GRSCs cases among 16 to measure the overall performance of GRSCS's Technology commercialization. Second, this paper assess the effectiveness of GRSCs to bring the better performance of technology commercialization. Third, this paper suggest soft program-centered technology commercialization model, rather institution and ceremonial-oriented one, for GRIs. Overall, the outcomes of this paper will contribute to accommodate the rule of GRSCs attaining goals set in the initial policy domain.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.134-139
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• 2008

A spirally arrayed nano-pattern is designed as a model pattern for the next generation optical storage media. The pattern consists off types of embossed rectangular dot, which are 50nm, 100nm, 150nm and 200nm in length and 50nm in width. The height of the dot is designed to be 50nm. The pitch of the spiral track of the pattern is 100nm. A ER(Electron resist) master for this pattern is fabricated by e-beam lithography process. The ER is first spin-coated to be 50nm thick on a Si wafer and then the model pattern is written on the coated ER layer by e-beam. After developing this pattern written wafer in the solution, a ER pattern master is fabricated. The most conventional e-beam machine can write patterns in orthogonal way, so we made our own pattern generator which can write the pattern in circular or spiral way. This program generates the patterns to be compatible with the e-beam machine from Raith(Raith 150). To fabricate 50nm pattern master precisely, a series of experiments were done including the design compensation for the pattern size, optimization of the dose, acceleration voltage, aperture size and developing. Through these experiments, we conclude that the higher accelerating voltages and smaller aperture size are better for mastering the nano pattern which is in order of 50nm. With the optimized e-beam lithography process, a spiral arrayed 50nm pattern master adopting PMMA resist was fabricated to have dimensional accuracy over 95% compared to the designed. Using this pattern master, a metal pattern stamp will be fabricated by Ni electro plating for injection molding of the patterned plastic substrate.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.40-44
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• 2017

The effect of weak dielectric silicone dioxide($SiO_2$) embedded in polyfluorene(PFO) emitting layer of polymer-based multi structure OLED was investigated. Indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/poly(9,9-di-n-octylfluorenyl-2,7-diyl)(PFO)/2,2,2"-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi)/aluminum(Al) structure OLED was fabricated by spin-coating method. Applied electric field causes some effect on $SiO_2$ in PFO layer. Thus, interaction between polymers and affected $SiO_2$ might generate electrical and luminance properties change. Experimental results, show the reduced threshold voltage of 6 V(from 23 V to 17 V). The maximum current density was rather increased from $71A/m^2$ to $610A/m^2$ and maximum brightness was also increased from $7.19cd/m^2$ to $41.03cd/m^2$, 9 and 6 times each. Additionally we obtained colour broadening result due to the increasing of blue-green band emission. Consequently we observed that electrical and luminance properties are enhanced by adding $SiO_2$ and identified the possibility of controlling the emission colour of OLED device according to colour broadening.

• Journal of Korea Technology Innovation Society
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• v.14 no.3
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• pp.552-577
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• 2011

We have analyzed technology transfer and commercialization process and factors affecting the outcomes of technology commercialization of public research institutes in Korea. A technology commercialization process model was presented as an input, intermediate outcomes/capabilities, output (outcome) structure using the structural equation model. Input variables include R&D input, technology commercialization strategy/support, collaboration, social capital. The model also includes R&D capabilities and technology commercialization performance as intermediate variable and output variable respectively. The technology commercialization performance was measured as the number of technology transfer and spin-off. We conducted survey and 88 institutes responded. Empirical results show that R&D input influence R&D capabilities and R&D capabilities influence the output of technology transfer and commercialization. Collaboration activities and social capital also appear to have a positive effect on the output. However, the effect of strategy and support on the output appear to be not statistically significant.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.626-631
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• 2007

New town development project which has manifold operations is usually on a large scale and its spin-off spreads widely. Although international new town development market is widely increasing, new town development market in Korea is now decreasing. Thus, Korean public new town development company which has a lot of business experiences in local new town development market is now facing the necessity of making a foray. This study had a Focus Group Interview with people who experienced in international construction market to set up the core factors of international new town development market. After that, Importance Performance Analysis and Content Analysis were performed with questionnaire to determine the present condition of Korean public new town development company.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1313-1314
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• 2007

This paper presents organic thin-film transistors (OTFTs) with poly(3-hexylthiophene)(P3HT) semiconductor and several polymeric dielectric materials of poly(vinyl phenol)(PVP), poly(vinyl alcohol)(PVA), and polyimide(PI) by using soluble process. The fabricated OTFT's have inverted staggered structure using transmission line method(TLM) pattern. In order to evaluate the electrical characteristics of the OTFT, capacitance-voltage(C-V) and current-voltage(I-V) were measured. C-V graphs were measured at several frequencies of 100 Hz, 1 kHz, and 1 MHz and ID-VDS graphs according to $V_{GS}$. The current on/off ratio and threshold voltage with each of PVP, PVA, and PI based OTFTs were measured to $10^3$, and -0.36, -0.41, and -0.62 V. Also, the calculated mobility with each of PVP, PVA, and PI was 0.097, 0.095, and 0.028 $cm^{2}V^{-1}s^{-1}$, respectively. In the cases of PVP and PVA, the hole mobility of P3HT was in excellent agreement with the published value of 0.1 $cm^{2}V^{-1}s^{-1}$.

• Polymer(Korea)
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• v.35 no.4
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• pp.370-374
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• 2011

A conductive PANI solution was successfully fabricated by doping with camphorsulfonic acid and the polymerization of aniline and the confirmation of doping were characterized by FTIR spectroscopy. In organic thin film transistors, PANI gate electrodes were spin-coated on a PES substrate and their conductivity variations were monitored by a 4-probe method with different annealing temperatures. The surface properties of PANI thin films were investigated by an AFM and an optical microscope, OTFTs with PANI gate electrode had characteristics of carrier mobility as large as 0.15 $cm^2$/Vs and on/off ratio of $2.4{\times}10^6$, Au gate OTFTs with the same configuration were fabricated to investigate the effect of polymer gate electrode for the comparison of device performances. We could obtain the comparable performances of PANI devices to those of Au gate devices, resulting in an excellent alternative as an electrode in flexible OTFTs instead of an expensive Au electrode.