• 제목/요약/키워드: barrier factor

검색결과 452건 처리시간 0.029초

표면 습식 식각 및 열처리에 따른 GaN 단일 나노로드 소자의 전기적 특성변화 (The Electrical Properties of GaN Individual Nanorod Devices by Wet-etching of the Nanorod Surface and Annealing Treatment)

  • 지현진;최재완;김규태
    • 한국전기전자재료학회논문지
    • /
    • 제24권2호
    • /
    • pp.152-155
    • /
    • 2011
  • Even though nano-scale materials were very advantageous for various applications, there are still problems to be solved such as the stabilization of surface state and realization of low contact resistances between a semiconducting nanowire and electrodes in nano-electronics. It is well known that the effects of contacts barrier between nano-channel and metal electrodes were dominant in carrier transportation in individual nano-electronics. In this report, it was investigated the electrical properties of GaN nanorod devices after chemical etching and rapid thermal annealing for making good contacts. After KOH wet-etching of the contact area the devices showed better electrical performance compared with non-treated GaN individual devices but still didn't have linear voltage-current characteristics. The shape of voltage-current properties of GaN devices were improved remarkably after rapid thermal annealing as showing Ohmic behaviors with further bigger conductivities. Even though chemical etching of the nanorod surfaces could cause scattering of carriers, in here it was shown that the most important and dominant factor in carrier transport of nano-electronics was realization of low contact barrier between nano-channel and metal electrodes surely.

CO/p a-SiC:H 계면의 버퍼층에 따른 비정질 실리콘 박막태양전지 동작특성 (Performances of a-Si:H thin-film solar cells with buffer layers at TCO/p a-SiC:H interface)

  • 이지은;장지훈;정진원;박상현;조준식;윤경훈;송진수;김동환;이정철
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
    • /
    • pp.32-32
    • /
    • 2009
  • 실리콘 박막 태양전지에서 전면 투명전도막(TCO)은 태양전지의 전기, 광학적 특성을 결정하는 중요한 기능을 한다. ZnO:Al TCO는 기존에 사용되던 $SnO_2:F$와는 비정질 실리콘(a-Si:H) 박막 태양전지의 윈도우 층으로 사용되는 p a-SiC:H와의 일함수(work function) 차이로 인해 접촉전위(contact barrier)를 형성하게 되며 이로 인해 태양전지의 충진율(fill factor)이 $SnO_2:F$에 비해 감소하는 단점을 보인다. 본 연구에서는 ZnO:Al/p a-SiC:H 계면의 접촉전위 발생원인 및 태양전지 충진율 감소현상에 관한 정확한 원인규명을 위해 다양한 특성을 갖는 버퍼층을 삽입하여 계면특성 및 태양전지의 동작특성을 분석하고자 한다.

  • PDF

Applying the Health Belief Model to college students' health behavior

  • Kim, Hak-Seon;Ahn, Joo;No, Jae-Kyung
    • Nutrition Research and Practice
    • /
    • 제6권6호
    • /
    • pp.551-558
    • /
    • 2012
  • The purpose of this research was to investigate how university students' nutrition beliefs influence their health behavioral intention. This study used an online survey engine (Qulatrics.com) to collect data from college students. Out of 253 questionnaires collected, 251 questionnaires (99.2%) were used for the statistical analysis. Confirmatory Factor Analysis (CFA) revealed that six dimensions, "Nutrition Confidence," "Susceptibility," "Severity," "Barrier," "Benefit," "Behavioral Intention to Eat Healthy Food," and "Behavioral Intention to do Physical Activity," had construct validity; Cronbach's alpha coefficient and composite reliabilities were tested for item reliability. The results validate that objective nutrition knowledge was a good predictor of college students' nutrition confidence. The results also clearly showed that two direct measures were significant predictors of behavioral intentions as hypothesized. Perceived benefit of eating healthy food and perceived barrier for eat healthy food to had significant effects on Behavioral Intentions and was a valid measurement to use to determine Behavioral Intentions. These findings can enhance the extant literature on the universal applicability of the model and serve as useful references for further investigations of the validity of the model within other health care or foodservice settings and for other health behavioral categories.

POCl3를 사용한 pn접합 소자에 관한 연구 (Study on the pn Junction Device Using the POCl3 Precursor)

  • 오데레사
    • 한국진공학회지
    • /
    • 제19권5호
    • /
    • pp.391-396
    • /
    • 2010
  • 실리콘 태양전지의 pn 접합 계면특성을 조사하기 위해서 p형 실리콘 기판 위에 전기로를 이용한 $POCl_3$ 공정을 통하여 n형의 불순물을 주입하여 pn 접합을 만들었다. n형 불순물의 확산되어 들어가는 공정시간이 길고 공정온도가 높을수록 면저항은 줄어들었다. n형 불순물의 주입이 많아질수록 pn 접합 계면에서의 전자친화도가 줄어들면서 면저항은 감소되었다. 면저항이 줄어든 이유는 pn 접합계면에서 전자홀쌍이 생성되면서 이동길이가 길어지고 재결합률이 감소하였기 때문이다. n형의 불순물 확산공정시간이 긴 태양전지 셀에서 F.F. 계수가 높게 나타났으며, 효율도 높게 나타났다.

VOD 스트리밍 서버 데이터를 위한 일치성 보장 알고리즘 개발 (Development of Consistency Algorithm for VOD Streaming Server Data)

  • 장승주
    • 전자공학회논문지CI
    • /
    • 제43권5호
    • /
    • pp.8-16
    • /
    • 2006
  • 본 논문에서는 VOD에서 스트리밍 데이터를 효율적으로 서비스할 수 있는 Consistency 알고리즘을 제시하고 개발한다. 미디어 데이터 서비스를 위해 하나의 미디어 데이터를 라운드 로빈 방식으로 스트라이핑하여 각 호스트의 저장 노드에 저장한다. 본 논문에서는 일반적인 계산 용도로 사용되는 매커니즘을 미디어 플레이 최소 단위인 (SH, GOP) 미디어 데이터에 서비스할 수 있도록 한다. VOD 시스템에서 RTP 패킷 데이터는 빠른 미디어 서비스 제공을 위하여 본 논문에서 제시한 consistency 알고리즘을 설계 및 구현하였다. 또한 이 알고리즘에 추가 기능으로 동기화에 따라 공유메모리에 존재하는 멀티미디어 데이터의 순서화된 서비스를 보장하는 것이다. 그리고 예상 페이징 기법을 적용하여 효율적인 버퍼링 기능을 보장하는 것이다. 그리고 본 논문에서 제시한 알고리즘에 대한 성능 평가를 실시하였다. 실험 결과 마지막 시점에 적용되는 베리어 알고리즘으로 인해 성능이 우수함을 알 수 있다.

성공적인 골유도재생술을 위한 봉합술 : 점막하 봉합법을 이용한 이중 봉합술의 예비 보고 (SUTURE TECHNIQUE FOR SUCCESSFUL GUIDED BONE REGENERATION ; PRELIMINARY REPORT OF DOUBLE LAYERED SUTURE TECHNIQUE WITH SUBGINGIVAL SUTURE)

  • 김영빈;조성대;임대호
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • 제31권1호
    • /
    • pp.86-91
    • /
    • 2009
  • The success of implants essentially depends on a sufficient volume of healthy bone at the recipient site during implant placement. In patients who have the severe alveolar bone resorption or pneumatized maxillary sinus, it should be performed that bone regeneration procedure before implant placement. Development of barrier membrane makes it possible that predictable result of alveolar bone reconstruction. Many kind of materials used for barrier membrane technique are introduced, non-absorbable or absorbable membranes. But, when operation site was ruptured with membrane exposure, bacterias can be grow up at the bone graft site. Then morphology and migration of fibroblast will be changed. It works as a negative factor on healing process of bone graft site. In oral and maxillofacial department of Chonbuk national university dental hospital, we use variable suture technique like as subgingival suture, vertical mattress suture, simple interrupted suture, if need, tenting suture after GBR or block bone graft. Within these suture technique, wound healing was excellent without complication, so now we take a report of suture technique in reconstruction of alveolar bone surgery.

VOD 스트리밍 데이터를 위한 Consistency 알고리즘 개발 (Development of Consistency Algorithm for VOD streaming Data)

  • 장승주
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2006년도 춘계종합학술대회
    • /
    • pp.729-732
    • /
    • 2006
  • 본 논문에서는 VOD 서 스트리밍 데이터를 효율적으로 서비스할 수 있는 Consistency 알고리즘을 제시하고 개발한다. 본 논문에서는 일반적인 계산 용도로 사용되는 barrier 메커니즘을 미디어 플레이 최소 단위인 (SH, GOP) 미디어 데이터에 서비스할 수 있도록 한다. VOD 시스템에서 RTP 패킷 데이터는 빠른 미디어 서비스 제공을 위하여 본 논문에서 제시한 consistency 알고리즘을 설계 및 구현하였다. 또한 이 알고리즘에 추가 기능으로 시간 동기화에 따라 공유메모리에 존재하는 멀티미디어 데이터의 순서화된 서비스를 보장하는 것이다. 그리고 예상 페이징 기법을 적용하여 효율적인 버퍼링 기능을 보장하는 것이다. 그리고 본 논문에서 제시한 알고리즘에 대한 성능 평가를 실시하였다.

  • PDF

이산화탄소를 이용한 ZTO 박막의 이동도와 안정성분석 (Element Analysis related to Mobility and Stability of ZTO Thin Film using the CO2 Gases)

  • 오데레사
    • 한국재료학회지
    • /
    • 제28권12호
    • /
    • pp.758-762
    • /
    • 2018
  • The transfer characteristics of zinc tin oxide(ZTO) on silicon dioxide($SiO_2$) thin film transistor generally depend on the electrical properties of gate insulators. $SiO_2$ thin films are prepared with argon gas flow rates of 25 sccm and 30 sccm. The rate of ionization of $SiO_2$(25 sccm) decreases more than that of $SiO_2$(30 sccm), and then the generation of electrons decreases and the conductivity of $SiO_2$(25 sccm) is low. Relatively, the conductivity of $SiO_2$(30 sccm) increases because of the high rate of ionization of argon gases. Therefore, the insulating performance of $SiO_2$(25 sccm) is superior to that of $SiO_2$(30 sccm) because of the high potential barrier of $SiO_2$(25 sccm). The $ZTO/SiO_2$ transistors are prepared to research the $CO_2$ gas sensitivity. The stability of the transistor of $ZTO/SiO_2$(25 sccm) as a high insulator is superior owing to the high potential barrier. It is confirmed that the electrical properties of the insulator in transistor devices is an important factor to detect gases.

3구 노즐을 이용한 플라즈마 가스 용존율 향상을 위한 플라즈마 공정의 최적화 (Optimization of Plasma Process to Improve Plasma Gas Dissolution Rate using Three-neck Nozzle)

  • 김동석;박영식
    • 한국환경과학회지
    • /
    • 제30권5호
    • /
    • pp.399-406
    • /
    • 2021
  • The dissolution of ionized gas in dielectric barrier plasma, similar to the principle of ozone generation, is a major performance-affecting factor. In this study, the plasma gas dissolving performance of a gas mixing-circulation plasma process was evaluated using an experimental design methodology. The plasma reaction is a function of four parameters [electric current (X1), gas flow rate (X2), liquid flow rate (X3) and reaction time (X4)] modeled by the Box-Behnken design. RNO (N, N-Dimethyl-4-nitrosoaniline), an indictor of OH radical formation, was evaluated using a quadratic response surface model. The model prediction equation derived for RNO degradation was shown as a second-order polynomial. By pooling the terms with poor explanatory power as error terms and performing ANOVA, results showed high significance, with an adjusted R2 value of 0.9386; this indicate that the model adequately satisfies the polynomial fit. For the RNO degradation, the measured value and the predicted values by the model equation agreed relatively well. The optimum current, gas flow rate, liquid flow rate and reaction time were obtained for the highest desirability for RNO degradation at 0.21 A, 2.65 L/min, 0.75 L/min and 6.5 min, respectively.

Development and validation of women's environmental health scales in Korea: severity, susceptibility, response efficacy, self-efficacy, benefit, barrier, personal health behavior, and community health behavior scales

  • Kim, Hee Kyung;Kim, Hyun Kyoung
    • 여성건강간호학회지
    • /
    • 제27권2호
    • /
    • pp.153-165
    • /
    • 2021
  • Purpose: This study aimed to develop the following scales on women's environmental health and to examine their validity and reliability: severity, susceptibility, response efficacy, self-efficacy, benefit, barrier, personal health behavior, and community health behavior scales. Methods: The item pool was generated based on related scales, a wide literature review, and indepth interviews on women's environmental health according to the revised Rogers' protection motivation theory model. Content validity was verified by three nursing professionals. Exploratory factor analysis, convergent validity, and internal consistency reliability were examined. Results: The scales included 10 items on severity, 11 on susceptibility, 10 on response efficacy, 14 on self-efficacy, 8 on benefits, 10 on barriers, 17 on personal health behavior, and 16 on community health behavior. Convergent validity with the environmental behavior scale for female adolescents was supported. The Cronbach's α values for internal consistency were good for all scales: severity, . 84; susceptibility, .92; response efficacy, .88; self-efficacy, .90; benefits, .91; barriers, .85; personal health behavior, .90; and community health behavior, .91. Conclusion: The evaluation of the psychometric properties shows that these scales are valid and reliable measures of women's environmental health awareness and behaviors. These scales may be helpful for assessing women's environmental health behaviors, thereby contributing to efforts to promote environmental health.