• Journal of Electrochemical Science and Technology
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• v.2 no.4
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• pp.193-197
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• 2011

The influences of the thickness and microstructure of Fe layer on the electrochemical performances of Fe/Si multilayer thin film anodes were investigated. The Fe/Si multilayer films were prepared by electron beam evaporation, in which Fe layer was deposited with/without simultaneous bombardment of Ar ion. The kinetics of Li insertion/extraction reactions in the early stage are slowed down with increasing the thickness of Fe layer, but such a slowdown seems to be negligible for thin Fe layers less than about $500{\AA}$. When the Fe layer was deposited with ion bombardment, even the $300{\AA}$ thick Fe layer significantly suppress Li diffusion through the Fe layer. This is attributed to the dense microstructure of Fe layer, induced by ion beam assisted deposition (IBAD). It appears that the Fe/Si multilayer films prepared with IBAD show good cyclability compared to the film deposited without IBAD.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.313-316
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• 1999

Organic semiconductors based on conjugated thiophene oligomer have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, a conjugated oligomer such as ${\alpha}$-sexithiophene (${\alpha}$-6T) thin films was prepared by the Organic Molecular Beam Deposition (OMBD), and various electrode materials were also deposited by a simple vacuum evaporation, respectively. Those films were photolithographically patterned for the electrical measurements. Electrical charact-erization of the thin film transistor with various channel length were executed and the field effect mobility of these thin film transistors were also calculated by the formula using the experimental data.

• Electrical & Electronic Materials
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• v.9 no.1
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• pp.44-50
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• 1996

In this study, Selenium device was fabricated by vacuum evaporation method with the substrate temperature at room temperature and its electrical and optical properties were investigated to be used in optical device. The film properties largely depended on the transmittance and annealing time, and improved with aging owing to stress release. We found that the photocurrent of the films increase linearly with light illumination. As a result, Selenium device made by this method yielded a short circuit current density of 10.5mA/$\textrm{cm}^2$, an open circuit voltage of 39OmV.

• Transactions on Electrical and Electronic Materials
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• v.4 no.1
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• pp.7-10
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• 2003

Single phase CuInS$_2$ thin film with the strongest diffraction peak (112) at diffraction angle (2$\theta$) of 27.7$^{\circ}$ and the second strongest diffraction peak (220) at diffraction angle (2$\theta$) of 46.25$^{\circ}$was well made with chalcopyrite structure at substrate temperature of 70$^{\circ}C$. annealing temperature of 250$^{\circ}C$, annealing time of 60 min. The CuInS$_2$ thin film had the greatest grain size of 1.2 Um when the Cu/In composition ratio of 1.03, where the lattice constant of a and c were 5.60${\AA}$ and 11.12${\AA}$, respectively. The Cu/In stoichiometry of the single-phase CuInS$_2$thin films was from 0.84 to 1.3. The film was p-type when tile Cu/In ratio was above 0.99 and was n-type when the Cu/In was below 0.95. The fundamental absorption wavelength, absorption coefficient and optical band gap of p-type CuInS$_2$ thin film with Cu/In=1.3 were 837nm, 3.OH 104 cm-1 and 1.48 eV, respectively. The fundamental absorption wavelength absorption coefficient and optical energy band gap of n-type CuInS$_2$ thin film with Cu/In=0.84 were 821 nm, 6.0${\times}$10$^4$cm$\^$-1/ and 1.51 eV, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.501-504
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• 2003

In this paper, for enhancement of property on a-Si:H TFTs We measure interface characteristics of ferroelectrics thin film and a-Si:H thin film. First, SrTiO$_3$ thin film is deposited bye-beam evaporation. Deposited films are annealed for 1 hour in N2 ambient at 150$^{\circ}C$ ∼ 600$^{\circ}C$. Dielectric characteristics of deposited SrTiO$_3$ films are very good because dielectric constant shows 50∼100 and breakdown electric field are 1∼1.5MV/cm. a-SiN:H,a-Si:H(n-type a-Si:H) are deposited onto SrTiO$_3$ film to make MFNS(Metal/ferroelectric/a-SiN:H/a-Si:H) by PECVD. After the C-V measurement for interface characteristics, MFNS structure shows no difference with MNS(Metal/a-SiN:H/a-Si:H) structure in C-V characteristics but the insulator capacitance value of MFNS structure is much higher than the MNS because of high dielectric constant of ferroelectrics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.212-212
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• 2009

Thermoelectric devices were used to wide range of application. At present, increasing the efficiency of these devices, in particular, through the preparation of materials showing a high thermoelectric figure of merit, Z, $Bi_2Te_3$ and $Sb_2Te_3$ thin films on Si substrates are deposited by flash evaporation method for thermopile sensor applications. In order to enhance the thermoelectric properties of the thin film, annealing in high vacuum is carried out in the temperature range from 200 to $350^{\circ}C$. The microstructure of the film is investigated by XRD and SEM. The resistivity and Seebeck coefficient of the films are measured by Van der Pauw method and hot probe method respectively. At elevating annealing temperature, the crystallinity and thermoelectrical properties of films are improved by increasing the size of grains. At excessive high annealing temperatures, it is shown that Seebeck coefficient of films is decreased because of Te evaporation. By optimizing the annealing conditions, it is possible to obtain a high performance thin film with a thermoelectric properties.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.99.1-99.1
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• 2012

The thin-film photovoltaic absorbers (CdTe and $Cu(In,Ga)Se_2$) can achieve solar conversion efficiencies of up to 20% and are now commercially available, but the presence of toxic (Cd,Se) and expensive elemental components (In, Te) is a real issue as the demand for photovoltaics rapidly increases. To overcome these limitations, there has been substantial interest in developing viable alternative materials, such as $Cu_2ZnSnS_4$ (CZTS) is an emerging solar absorber that is structurally similar to CIGS, but contains only earth abundant, non-toxic elements and has a near optimal direct band gap energy of 1.4 - 1.6 eV and a large absorption coefficient of ~104 $cm^{-1}$. The CZTS absorber layers are grown and investigated by various fabrication methods, such as thermal evaporation, e-beam evaporation with a post sulfurization, sputtering, non-vacuum sol-gel, pulsed laser, spray-pyrolysis method and electrodeposition technique. In the present work, we report an alternative aqueous chemical approach based on chemical bath deposition (CBD) method for large area deposition of CZTS thin films. Samples produced by our method were analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, absorbance and photoluminescence. The results show that this inexpensive and relatively benign process produces thin films of CZTS exhibiting uniform composition, kesterite crystal structure, and some factors like triethanolamine, ammonia, temperature which strongly affect on the morphology of CZTS film.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.8
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• pp.7-12
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• 2010

In this paper, $C_{60}$ based Organic thin film transistor OTFTs) have been fabricated using BPhen(Bathophenanthroline) and BPhen doped with Cs interlayers between $C_{60}$ active layer and Al electrodes to improve the electrical performance. The addition of the BPhen layer resulted in enhanced performances by reducing surface roughness between organic-metal interface. And the contact resistance was reduced by using the BPhen doped with Cs interlayer with co-evaporation method. These performances suggests that the $C_{60}$ based OTFT with BPhen doped with Cs interlayer is a promising application in the fabrication of n-type organic transistors.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.34-38
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• 1999

$PbTiO_3$(PT)thin films were prepared by simultaneous of $TiO_2$ and PbO on Si(100) substrate using metaloganic chemical vapor deposition (MOCVD). Titanium tetra-isopropoxide (TTIP) and $Pb(TMHD)_2$were used as source materials. As evaporation temperature and flow rate of TTIP were examined the crystal structure of PT thin films using XRD with setting deposition temperature, flow rate of Pb, and total flow rate of $520^{\circ}C$, 30 sccm, and 750 sccm, respectively. PT thin films could be deposited under 48~$50^{\circ}C$ and 18~22sccm of evaporation temperature and flow rate of TTIP, respectively. It was found that lead, oxygen, and silicon diffused at the iaterface between the film and the substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.27-27
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• 1998

진공기술의 응용과 진공환경의 이용은 더 이상 논하지 않더라도 산업 전반에 그 충요성이 점점 더 커가고 있다. 이러한 여건에도 불구하고 진공율 이용하는 system 개밟의 국산화는 수 입하는 system으$\mid$ 수에 비하여 절대적으로 부족하며, 또한 개발하는 system의 자동화는 거의 이 루어지지 않고 있으며, 자동화된 진공판련 system은 거의 대부분 수입에 의흔하고 있다. 실험 실 규모에서부터 System올 하나하나 개밭하고, 이톨 자동화하는 노력과 일이 진행됨다면 산업 응용에 있어서도 자연스럽게 자동화된 system으$\mid$ 개발이 이루어 질 것이다 .. system 자동화는 상 품수명의 단축과 이에 따른 다품종 소량을 요구하는 시장수요에 대응하고, 인력절감과 고풀짙 화로 생산성 향상의 요구에 대응하기 위하여 필요하다. 본 연 구에 서 는 e-beam evaporator로 evaporation하면 서 ion beam으로 assist하여 thin film율 제 작하는 IBAD vacuum system율 싫 계 및 제 작하고[1,2], PLC[3,떼톨 이 용하여 system 자동화톨 하였다 .. thin film 제작 process는 먼저 기본 진공상태로 만뚫고 난 뒤, e-beam evaporator로 e evaporation하면서 ion beam source로 assist하여 substrate 011 thin film율 제조한다 226;. thin film올 제 조하면서 thickness monitor로 sample의 thickness rate톨 control 하고, sample의 균얼성과 밀착 성을 고려하여 substrate톨 rotation 및 heating 할 수 있도록 싫계, 제작하였다. 양질의 박막올 제조하기 위해서 진공환경이 좋은 상태로 제공되어야 한다. 이톨 위하여 oil free operation 0 I 가 능한 dry pump와 turbo molecular pump로 고진공 배기 하였다. 진공도의 흑점은 thermal effect 툴 고려하여 cold cathode ion gauge률 사용하였고, intro chamber와 main chamber 사이에는 g gate valve톨 설치하여 벌도로 운용되도록 하였다. 이러한 process를 박막의 두께, 진공도, 시 간, 온도, 공정 동의 조건올 기훈으로 자동화한 것이다. 또한 정전과 단수에 대한 interlock 기능 도 고려하였다.하였다.