• Title/Summary/Keyword: Work-function

검색결과 3,467건 처리시간 0.038초

산소 플라즈마로 처리한 ITO(Indium-Tin-Oxide)에 대한 일함수 변화 (Changes in Work Function after O-Plasma Treatment on Indium-Tin-Oxide)

  • 김근영;오준석;최은하;조광섭;강승언;조재원
    • 한국진공학회지
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    • 제11권3호
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    • pp.171-175
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    • 2002
  • Indium-Tin-Oxide(ITO)에 대해 산소 플라즈마 처리를 한 후 일함수에 대한 변화를 $\gamma$-집속 이온빔을 사용하여 조사하였다. ITO의 표면이 산소 플라즈마 처리를 보다 많이 경험할수록 표면저항이나 일함수는 높아졌다. Auger 전자 분광법을 이용해 표면의 화학적 분석을 해본 결과 산소는 증가한 반면 주석은 감소하였다. 표면 일함수와 표면 저항의 증가는 ITO 표면에서의 산소와 주석의 변화와 관계가 있는 것으로 여겨진다.

Effect of Ar ion Sputtering on the Surface Electronic Structure of Indium Tin Oxide

  • Lee, Hyunbok;Cho, Sang Wan
    • Applied Science and Convergence Technology
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    • 제25권6호
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    • pp.128-132
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    • 2016
  • We investigated the effect of Ar ion sputtering on the surface electronic structure of indium tin oxide (ITO) using X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) measurements with increasing Ar ion sputtering time. XPS measurements revealed that surface contamination on ITO was rapidly removed by Ar ion sputtering for 10 s. UPS measurements showed that the work function of ITO increased by 0.2 eV after Ar ion sputtering for 10 s. This increase in work function was attributed to the removal of surface contamination, which formed a positive interface dipole relative to the ITO substrate. However, further Ar ion sputtering did not change the work function of ITO although the surface stoichiometry of ITO did change. Therefore, removing the surface contamination is critical for increasing the work function of ITO, and Ar ion sputtering for a short time (about 10 s) can efficiently remove surface contamination.

박막 게이트 산화막에 대한 Ru-Zr 금속 게이트의 신뢰성에 관한 연구 (A Study on the Reliability of Ru-Zr Metal Gate with Thin Gate Oxide)

  • 이충근;서현상;홍신남
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권4호
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    • pp.208-212
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    • 2004
  • In this paper, the characteristics of co-sputtered Ru-Zr metal alloy as gate electrode of MOS capacitors have been investigated. The atomic compositions of alloy were varied by using the combinations of relative sputtering power of Ru and .Zr. C-V and I-Vcharacteristics of MOS capacitors were measured to find the effective oxide thickness and work function. The alloy made of about 50% of Ru and 50% of Zr exhibited an adequate work function for nMOS. C-V and I-V measurements after 600 and $700^{\circ}C$ rapid thermal annealing were performed to prove the thermal and chemical stability of the Ru-Zr alloy film. Negligible changes in the accumulated capacitance and work function before and after annealing were observed. Sheet resistance of Ru-Zr alloy was lower than that of poly-silicon. It can be concluded that the Ru-Zr alloy can be a possible substitute for the poly-silicon used as a gate of nMOS.

Control the Work Function and Plasmon Effect on Graphene Surface Using Metal Nanoparticles for High Performance Optoelectronics

  • Park, Si Jin;Kang, Seong Jun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.166.1-166.1
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    • 2014
  • We have controlled the graphene surface in two ways to improve the device performance of optoelectronics based on graphene transparent conductive films. We controlled multilayer graphene (MLG) work function and localized surface plasmon resonance wavelength using a silver nanoparticles formed on graphene surface. Graphene substrates were prepared using a chemical vapor deposition and transfer process. Various size of silver nanoparticles were prepared using a thermal evaporator and post annealing process on graphene surface. Silver nanoparticles were confirmed by using scanning electron microscopy (SEM). Work functions of graphene surface with various sizes of Ag nanoparticles were measured using ultraviolet photoelectron spectroscopy (UPS). The result shows that the work functions of MLG could be controlled from 4.39 eV to 4.55 eV by coating different amounts of silver nanoparticles while minimal changes in the sheet resistance and transmittance. Also the Localized surface plasmon resonance (LSPR) wavelength was investigated according to various sizes of silver nanoparticles. LSPR wavelength was measured using the absorbance spectrum, and we confirmed that the resonance wavelength could be controlled from 396nm to 425nm according to the size of silver nanoparticles on graphene surface. To confirm improvement of the device performance, we fabricated the organic solar cell based on MLG electrode. The results show that the work function and plasmon resonance wavelength could be controlled to improve the performance of optoelectronics device.

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Work Hours and Cognitive Function: The Multi-Ethnic Study of Atherosclerosis

  • Charles, Luenda E.;Fekedulegn, Desta;Burchfiel, Cecil M.;Fujishiro, Kaori;Hazzouri, Adina Zeki Al;Fitzpatrick, Annette L.;Rapp, Stephen R.
    • Safety and Health at Work
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    • 제11권2호
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    • pp.178-186
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    • 2020
  • Background: Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function. Methods: Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44-84 years) reported hours per week worked in all jobs in Exams 1 (2000-2002), 2 (2002-2004), 3 (2004-2005), and 5 (2010-2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work. Results: Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = -0.55, 95% CI = -0.99, -0.09) and (β = -0.80, -1.51, -0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = -0.80, -1.52, -0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function. Conclusion: Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

워크샘플링(Work Sampling)에 의한 병원급식의 작업측정 사례연구 (A Case Study on the Work Measurement of Hospital Foodservice by the Work Sampling Methodology)

  • 차진아
    • Journal of Nutrition and Health
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    • 제24권6호
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    • pp.547-559
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    • 1991
  • The purposes of this study were to : a)determine the percentage of labor activities expen-ded in various work functionsof hospital foodservice b)estimate the labor time utilized in each work functions c)investigate the overall work patterns of hospital foodservice and d)provide the basic data for effective labor control This study was conducted in two hospitals with 1300 and 1200 ed capacities and every employees of the dietary department were included in 10days work measurement. Work sampling methodology developed by Donaldson and Ostenso was modified and used for observing overall activities of hospital dietary department. Consistency of data and observa-tion period were verified by 3$\delta$ control chart and control chart. Observed data were satisfied with confidence level of 95% and confidence interval of $\pm$0.05, The results of this study were as follows: 1) The direct work function indirect work function and delay were 74.8%, 9.2%, 16.0% respectively with A hospital and 82.2% 7.2%, 10.6% respectively with B hospital 2) The productivity indices of direct work indirect work and delay were 9.05 min/meal 1.12 min/meal 1.94 min/meal respectively and total 12.11 minutes were utilized per meal served in A hospital and 10.72 min/meal 0.94 min/meal 1.38 min/meal respectively and total 13.04 minutes were utilized per meal served in B hospital 3) Full time equivalent(FTE) utilized in daily work of irect work indirect work and delay were 62.24 men 7.69 men 13.35 men respectively in A hospital and 64.09 men 5.63 men 8.22 men respectively in B hospital. 4) The contents of work activities of each employee group showed that delay time of the service personnel group was more than any other employee groups in both A hospital and B hospital 5) Examination of daily work schedule by time intervals showed that transportation work function was carried out all day so it is necessary to improve this work.

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목록의 집중기능을 향상시키는 '원형' 개념에 관한 연구 (A Study on a Concept of 'Prototype' for Enhancing the Collocation Function of Catalog)

  • 이혜원
    • 한국비블리아학회지
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    • 제22권3호
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    • pp.91-107
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    • 2011
  • 저작은 목록의 집중기능에 중요한 역할을 하는 서지 개체이다. 본 연구에서는 저작의 개념을 재분석하고, 이미 공표된 FRBR 저작의 개념을 보완할 수 있는 새로운 방안을 모색하고자 하였다. 저작의 집중기능을 향상시킬 수 있는 방안으로 저작보다 한 차원 높은 '원형' 개체를 선언하였고, 원형과 관련된 속성 및 관계를 FRBR 모형과 연결하여 설명하였다.

에프터서비스 업무분야의 스마트워크 구축 - 엘리베이터 산업을 중심으로 - (Development of a Smart work for After Service Business - Focused on Elevator industry -)

  • 김성균;유우식
    • 정보화연구
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    • 제10권2호
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    • pp.273-281
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    • 2013
  • 스마트워크의 유형은 모바일 기기등을 이용하여 현장에서 업무를 수행하는 모바일오피스, 자택에서 본사 통신망에 접속하여 업무를 수행하는 재택근무, 자택인근 원격사무실에서 근무하는 스마트워크센터근무와 같은 형태를 의미하며 기존 사무실개념에 비하여 공간과 시간의 벽을 극복할 수 있도록 도와준다. 본 논문에서는 엘리베이터 산업의 에프터서비스 산업문야에서 모바일 오피스 시스템을 개발하는 과정을 설명하는데 개발된 시스템은 A/S Work이라 명명 하였다. 개발된 A/S Work 시스템은 M 엘리베이터사의 에프터서비스에 활용되어 기존시스템과 비교하면 다음과 같은 장점을 가진다. 1) 고객별 작업전후 사진관리 2) 현장에서의 고객만족도조사 3) 작업일지관리 앱 4) 작업자 근태관리 5) 그룹 SMS 기능.

Combinatorial studies on the work function characteristics for Nb or Zn doped indium-tin oxide electrodes

  • Heo, Gi-Seok;Kim, Sung-Dae;Park, Jong-Woon;Lee, Jong-Ho;Kim, Tae-Won
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.159-159
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    • 2008
  • Indium-tin oxides (ITO) films have been widely used as transparent electrodes for optoelectronic devices such as organic light emitting diodes (OLEDs), photovoltaics, touch screen devices, and flat-paneldisplay. In particular, to improve hole injection efficiency in OLEDs, transparent electrodes should have high work-function besides their transparency and low resistivity. Nevertheless, few studies have been made on engineering the work function of ITO for use as an efficient anode. In this study, the effects of a wide range of Nb or Zn doping rate on the changes in work functions of ITO anode were investigated. The Nb or Zn doped ITO films were fabricated on glass substrates using combinatorial sputtering system which yields a linear composition spread of Nb or Zn concentration in ITO films in a controlled manner by co-sputtering two targets of ITO and Nb2O5 or ITO and ZnO. We have also examined the resistivity, transmittance, and other structural properties of the Nb or Zn-doped ITO films. Furthermore, OLEDs employing Nb or Zn-doped ITO anodes were fabricated and the device performances were investigated concerned with the work function changes.

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친환경 정비공법 선정 지원을 위한 웹기반 정보시스템 구축 (Development for Eco-Design of Hydraulic Structures based on Web-based Information System)

  • 조영권;김관호;김한중;최수명
    • 한국농공학회논문집
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    • 제50권1호
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    • pp.95-106
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    • 2008
  • Eco-friendly material and implementation methods have become important along with the existing standardized maintenance concept for the irrigation and flood control. However, the intrinsic function of the hydraulic structure is water supply and disaster prevention. Therefore, the material and work methods should be considered both eco-friendliness, durability and safety which are prerequisite elements to maintain the engineering function. In this study eco-friendly material and work methods would be classified into the vegetation based system, eco-friendly concrete system and stone-material system according to the characteristics of material. The quality standard for durability followed KS specification and related regulations. The quality standard for safety and eco-friendliness was set after literature review, and the database was developed using the standard. The structure applicable to onsite - the eco-friendly material and work method were classified based on the function and material of the hydraulic structure. Finally, database has been established for convenient management and selection of the proper material and work method. The eco-friendly material and work method could be searched easily for the convenience of the users, and the web-based data system has been developed for continuous registration of the material and work methods to be developed in the future.