• Title/Summary/Keyword: charge carrier

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액정을 함유하는 유기 광도점체의 전하 수송착체에 의한 Charge-Carrier수송 특성과 형광거동 (Charge-Carrier Transport Properties and Fluorescence Behaviors Depending on Charge Transport Complex of Organic Photoconductor Containing Liquid Crystal)

  • 이봉;정선영;문두경
    • 폴리머
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    • 제25권5호
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    • pp.719-727
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    • 2001
  • 유기광도전체에 있어서의 액정은 종래의 분자 배향성을 가지지 않는 비정성 고체계와는 달리 분자 배향성을 가지기 때문에 분자 사이의 질서도가 높아지게 되고, charge-carrier의 hopping을 방해하는 hopping site의 공간적인 틈이 작아져 고 이동도의 특성을 가질수 있다. 본 연구에서는 유기광도전체의 전하 수송층에 액정5CT를 혼합하여, charge-carrier수송특성에 있어서의 액정5CT의 영향을 관찰하였다. 액정5CT를 함유한 유기광도전체는 액정의 혼합비가 증가함에 따가 초기전위는 증가하였으며, 암감쇄는 감소하는 경향을 나타내었다. 감도는 5CT를 TNF와 OXD 각자에 대하여 40 wt%로 혼합한 시료의 경우에 가장 우수하게 나타났다. 형광거동을 관찰한 결과, 이는 전하수송재료와 액정5CT의 전하 수송착체에 의한 것으로, 액정5CT를 TNF와 OXD 각각에 대하여 40 wt%로 혼합한 시료의 경우가 다른 시료에 비해 전하 수송착체가 가장 잘 형성되어, 성공을 잘 수송하기 때문으로 나타났다.

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Cholestric 액정 Cholesteryl Benzoate에서 Drift Mobility측정 (Electrical Drift Mobility in the Cholesteryl Benzoate)

  • 강태원;김화택
    • 대한전자공학회논문지
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    • 제15권2호
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    • pp.19-21
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    • 1978
  • Cholesteryl Benzoate 액정에서 전류 수송기구를 규명하기 위하여 charge carrier의 어i도 mobilits를 극성 반전법을 사용하여 140∼185℃의 온도 영 역에서 측정했다. charge carrier의 drift mobilits는 주위온도가 증가함에 따라 2.5×10-7㎠/V.sec에서 2.0×10-6㎠/V.sec까지 증가했다. 이 실험결과로 부터 전류 수송기구는 ionic기구로 설명할 수 있다.

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수명시간에 따른 NPT-IGBT의 N-drift 영역에서의 과잉소수 캐리어와 전하량 분석 (Analysis of excess minority carrier and charge wish lifetimes in N-dirft region of NPT-IGBT)

  • 류세환;이용국;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.844-847
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    • 2001
  • In this work, transient characteristics of the Non-Punch Through(NPT) Insulated Gate Bipolar Transistor(IGBT) has been studied. we has analyzed with lifetimes excess minority carrier injected into N-dirft, base region of IGBT's BJT part and accumulated charge of on-state which affected swiching characteristic. In this paper, excess minority carrier and charge distribution in active base region is expressed analytically. This analysis proposed optical trade-off between lifetimes and accumulated charge for decreasing switching losses because charge result in switching loss when device was tuned off.

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Charge Confinement and Interfacial Engineering of Electrophosphorescent OLED

  • Chin, Byung-Doo;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1203-1205
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    • 2007
  • Confinement of charge carrier and exciton is the essential factor for enhancing the efficiency and stability of the electrophosphorescent devices. The interplay between the properties of emitters and other adjacent layers are studied based on the physical interpretation with difference of energy level, charge carrier mobility, and corresponding charge-trapping behavior.

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DYNAMIC CHARGE CARRIER TRANSPORT BEHAVIORS IN ZIRCONIUM OXIDE FOR NUCLEAR CLADDING MATERIALS

  • IL-KYU PARK;SANG-SEOK LEE;YONG KYOON MOK;CHAN-WOO JEON;HYUN-GIL KIM
    • Archives of Metallurgy and Materials
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    • 제65권3호
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    • pp.1063-1067
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    • 2020
  • Dynamic charge carrier transport behavior in the zirconium (Zr) oxide was investigated based on the frequency-dependent capacitance-voltage (C-V) and temperature-dependent current-voltage (I-V) measurements. The Zr oxide was formed on the ZIRLO and newly developed zirconium-based alloy (NDZ) by corrosion in the PWR-simulated loop at 360℃. The corrosion test for 90 days showed that the NDZ exhibits better corrosion resistance than ZIRLO alloy. Based on the C-V measurement, dielectric constant values for the Zr oxide was estimated to be 11.28 and 11.52 for the ZIRLO and NDZ. The capacitance difference between low and high frequency was larger in the ZIRLO than in the NDZ, which was attributed to more mobile electrical charge carriers in the oxide layer on the ZIRLO alloy. The current through the oxide layers on the ZIRLO increased more drastically with increasing temperature than on the NDZ, which indicating that more charge trap sites exist in the ZIRLO than in NDZ. Based on the dynamic charge carrier transport behavior, it was concluded that the electrical charge carrier transport within the oxide layers was closely related with the corrosion behavior of the Zr alloys.

Azo기를 가지는 액정의 광 이성화에 따른 유기 광전도체의 carrier 수송 특성 (Charge-carrier Transport Properties of Organic Photoconductor by Photo-isomerization of Liquid Crystal with Azo Group)

  • 이봉;성정희;문창권
    • 한국재료학회지
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    • 제9권5호
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    • pp.473-477
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    • 1999
  • Xerographic properties of double-layer photoconductor doped with 4-butyl-4'-methoxyazobenzene (BMAB) as charge-carrier transport material were investigated. BMAB can undergo reversible trans-cis isomerization by light with appropriate wavelength. In the results of measured surface voltage properties for photoconductor doped with BMAB, TNF: BMAB(4-wt%) sample with trans form showed the lowest dark decay, the lowest residual voltage, and the highest sensitivity among cis form. The trans isomer of BMAB has ordering orientation because the molecule possesses a rodlike shape, while the cis isomer has random orientation due to its bent shape. Therefore the molecular arrangement of trans form enhanced charge-carrier transport mobility.

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Wet 게이트 산화막과 Nitride 산화막 소자의 특성에 관한 연구 (A Study on Characteristics of Wet Gate Oxide and Nitride Oxide(NO) Device)

  • 이용희;최영규;류기한;이천희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.970-973
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    • 1999
  • When the size of the device is decreased, the hot carrier degradation presents a severe problem for long-term device reliability. In this paper we fabricated & tested the 0.26${\mu}{\textrm}{m}$ NMOSFET with wet gate oxide and nitride oxide gate to compare that the characteristics of hot carrier effect, charge to breakdown, transistor Id_Vg curve and charge trapping using the Hp4145 device tester As a result we find that the characteristics of nitride oxide gate device better than wet gate oxide device, especially a hot carrier lifetime(nitride oxide gate device satisfied 30years, but the lifetime of wet gate oxide was only 0.1year), variation of Vg, charge to breakdown and charge trapping etc.

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PMOSFET에서 Hot Carrier Lifetime은 Hole injection에 의해 지배적이며, Nano-Scale CMOSFET에서의 NMOSFET에 비해 강화된 PMOSFET 열화 관찰 (PMOSFET Hot Carrier Lifetime Dominated by Hot Hole Injection and Enhanced PMOSFET Degradation than NMOSFET in Nano-Scale CMOSFET Technology)

  • 나준희;최서윤;김용구;이희덕
    • 대한전자공학회논문지SD
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    • 제41권7호
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    • pp.21-29
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    • 2004
  • 본 논문에서는 Dual oxide를 갖는 Nano-scale CMOSFET에서 각 소자의 Hot carrier 특성을 분석하여 두 가지 중요한 결과를 나타내었다. 하나는 NMOSFET Thin/Thick인 경우 CHC stress 보다는 DAHC stress에 의한 소자 열화가 지배적이고, Hot electron이 중요하게 영향을 미치고 있는 반면에, PMOSFET에서는 특히 Hot hole에 의한 영향이 주로 나타나고 있다는 것이다. 다른 하나는, Thick MOSFET인 경우 여전히 NMOSFET의 수명이 PMOSFET의 수명에 비해 작지만, Thin MOSFET에서는 오히려 PMOSFET의 수명이 NMOSFET보다 작다는 것이다. 이러한 분석결과는 Charge pumping current 측정을 통해 간접적으로 확인하였다. 따라서 Nano-scale CMOSFET에서의 NMOSFET보다는 PMOSFET에 대한 Hot camel lifetime 감소에 관심을 기울여야 하며, Hot hole에 대한 연구가 진행되어야 한다고 할 수 있다.

Effect of Charge Carrier Lipid on Skin Penetration, Retention, and Hair Growth of Topically Applied Finasteride-Containing Liposomes

  • Lee, Sang-Im;Nagayya-Sriraman, Santhosh-Kumar;Shanmugam, Srinivasan;Baskaran, Rengarajan;Yong, Chul-Soon;Yoon, Sang-Kwon;Choi, Han-Gon;Yoo, Bong-Kyu
    • Biomolecules & Therapeutics
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    • 제19권2호
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    • pp.231-236
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    • 2011
  • The aim of this study was to investigate the effect of charge carrier lipid on the skin penetration, retention, and hair growth of topically applied finasteride-containing liposomes. Finasteride-containing liposomes were prepared by traditional thin film hydration method using Phospholipon$^{(R)}$ 85 G and cholesterol with or without charge carrier lipid (1,2 dimyristoyl-sn-glycero-3-phosphate or 1,2-dioleoyl-trimethylammonium-propane for anionic and cationic charge, respectively). Freshly prepared finasteride-containing liposome suspension was applied on the hairless mouse skin, and skin penetration and retention were measured using Keshary-Chien diffusion cell. Non-liposomal formulation (ethanol 10% solution containing 0.5 mg/ml of FNS) was also used as a control. The amount of finasteride in the diffusion cell and mouse skin was measured by HPLC. The hair growth was evaluated using depilated male C57BL/6N mice. Mean particle size of all finasteride-containing liposomes was less than a micron, and polydispersity index revealed size homogeneity. Skin penetration and retention studies showed that significantly less amount of finasteride was penetrated when applied as anionic liposome while more amount of the drug was retained. Specifically, in liposome prepared with 10% anionic charge carrier lipid, penetration was 12.99 ${\mu}g/cm^2$ while retention was 79.23 ${\mu}g/cm^2$ after 24 h of application. In hair growth study, finasteride-containing anionic liposomes showed moderate efficacy, but the efficacy was not found when applied as cationic liposomes. In conclusion, topical application of finasteride using anionic liposome formulation appears to be useful option for the treatment of androgenetic alopecia to avoid systemic side effects of the drug.

NMOSFET의 제조를 위한 습식산화막과 질화산화막 특성에 관한 연구 (A Study on Characteristics of Wet Oxide Gate and Nitride Oxide Gate for Fabrication of NMOSFET)

  • 김환석;이천희
    • 정보처리학회논문지A
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    • 제15A권4호
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    • pp.211-216
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    • 2008
  • 본 논문에서는 핫 케리어 효과, 항복전압 전하, 트랜지스터 Id Vg 특성곡선, 전하 트래핑, SILC와 같은 특성들을 비교하기 위하여 HP 4145 디바이스 테스터를 사용하여 습식 산화막과 질화 산화막으로된 $0.2{\mu}m$ NMOSFET를 만들어 측정하였다. 그 결과 질화 산화막으로 만들어진 디바이스가 핫 케리어 수명(질화 산화막은 30년 이상인 반면에 습식 산화막 소자는 0.1년임), Vg의 변화, 항복전압, 전계 시뮬레이션, 전하 트래핑면에서도 습식 산화막 소자보다 우수한 결과를 얻을 수 있었다.