• Title/Summary/Keyword: Interfacial layer

Search Result 674, Processing Time 0.039 seconds

Fabrication and Impact Properties of $Nb/MoSi_2-ZrO_2$ Laminate Composites ($Nb/MoSi_2-ZrO_2$ 적층복합재료의 제조 및 충격특성)

  • Lee, Sang-Pill;Yoon, Han-Ki;Kong, Yoo-Sik
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.29-34
    • /
    • 2002
  • [ $Nb/MoSi_2-ZrO_2$ ] laminate composites have been successfully fabricated by alternately stacking $MoSi_2-ZrO_2$ powder layer and Nb sheet, followed by hot pressing in a graphite mould. The fabricating parameters were selected as hot press temperatures. The instrumented Charpy impact test was carried out at the room temperature in order to investigate the relationship between impact properties and fabricating temperatures. The interfacial shear strength between $MoSi_2-ZrO_2$ and Nb, which is associated with the fabricating temperature and the growth of interfacial reaction layer, is also discussed. The plastic deformation of Nb sheet and the interfacial delamination were macroscopically observed. The $Nb/MoSi_2-ZrO_2$ laminate composites had the maximum impact value when fabricated at 1623K, accompanying the increase of fracture displacement and crack propagation energy. The interfacial shear strength of $Nb/MoSi_2-ZrO_2$ laminate composites increased with the growth of interfacial reaction layer, which resulted from the increase of fabricating temperature. there is an appropriate interfacial shear strength for the enhancement of impact value of $Nb/MoSi_2-ZrO_2$ laminate composites. A large increase of interfacial shear strength restrains the plastic deformation of Nb sheet.

  • PDF

Study on the Evaluation for the Property of Mo-Si Multilayers (Mo/Si 다층박막의 특성 평가에 관한 연구)

  • 허성민;김형준;이동현;이승윤;이영태
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.8 no.2
    • /
    • pp.15-18
    • /
    • 2001
  • The Mo/si multilayer for EUV lithography was deposited using magnetron sputtering system. The multilayers were characterized using the cross-sectional transmission electron microscope (TEM) and low/high angle X-ray diffraction (XRD). The microstructure of Mo and Si was highly textured structure and amorphous, respectively. The well-defined low angle XRD peaks implies a well-defined multilayer structure. The interfacial layer of Mo-on-Si was thicker than Si-on-Mo interfacial layer.

  • PDF

Improved Efficiency by Insertion of TiO2 Interfacial Layer in the Bilayer Solar Cells

  • Xie, Lin;Yoon, Soyeon;Kim, Kyungkon
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.432.1-432.1
    • /
    • 2016
  • We demonstrated that the power conversion efficiency (PCE) of bilayer solar cell was significantly enhanced by inserting interfacial layer between the organic bilayer film and the Al electrode. Moreover, the water contact angle shows that the bilayer solar cells suffer from the undesirable surface component which limits the charge transport to the Al electrode. The AFM measurement has revealed that the pre- and post-thermal annealing treatments results in different morphologies of the interfacial layer which is critical for the higher PCE of the bilayer solar cells. Furthermore we have investigated the electrical properties of the bilayer solar cells and obtained insights into the detailed device mechanisms. The transient photovoltage measurements suggests that the significantly enhanced Voc is caused by reducing the recombination at the interface between the organic films and the Al electrode. By inserting the TiO2 layer between the bilayer film and Al electrode, the open circuit voltage (Voc) was increased from 0.37 to 0.66V. Consequently, the power conversion efficiency (PCE) of bilayer solar cells was significantly enhanced from 1.23% to 3.71%. As the results, the TiO2 interfacial layer can be used to form an ohmic contact layer, serveing as a blocking layer to prevent the penetration of the Al, and to reduce the recombination at the interface.

  • PDF

Studies on the Vibration Controllability of Smart Structure Depending on the Interfacial Adhesion Properties of Composite Materials (복합재료내의 계면 접착 특성에 따른 지능형 구조물의 진동제어에 관한 연구)

  • 한상보;박종만;차진훈
    • Journal of KSNVE
    • /
    • v.8 no.6
    • /
    • pp.1093-1102
    • /
    • 1998
  • The success of controllability of smart structures depends on the quality of the bonding along the interface between the main structure and the attached sensing and acuating elements. Generally, the analysis procedures neglect the effect of the interfacial bond layer or assume that this bond layer behaves like viscoelastic material. Three different bond layers. two modified epoxy adhesives, and one isocyanate adhesive were prepared for their toughness and moduli. Bond layer of the chosen adhesive provides an almost perfect bonding condition between the composite structure and the PZT while bended significantly like arrow-shape. The perfect bonding condition is tested by considering various material properties of the bond layers. and based on this perfect bonding condition, the effects of the interfacial bond layer on the dynamic behavior and controllability of the test structure is experimentally studied. Once the perfect bonding condition is achieved. dynamic effects of the bond layer itself on the dynamic characteristics of the main structure is negligible. but the contribution of the attached PZT elements on the stiffness of the multi-layered structure becomes significant when the thickness of the bond layer increased.

  • PDF

Efficiency enhancement of Organic Light Emitting Diodes by the AlON interfacial Layer (산소질화알루미늄 계면층에 의한 유기발광 소자의 효율 향상)

  • Park, Hyung-Jun;Hai, Jin Zheng;Nam, Eun-Kyoung;Jung, Dong-Geun;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.388-389
    • /
    • 2007
  • In this work, Organic Light Emitting Diodes using Aluminum-Oxynitride as a hole-injecting interfacial have been fabricated. This interfacial layer is inserted at the ITO/N,NV-diphenyl-N, NV-bis(3-methylphenyl)-1,1V-diphenyl-4,4V-diamine (TPD) interface. The brightness and efficiency of the device with the AION film is higher than that of the device without it. The enhancements are attributed to an improved balance of hole and electron injections due to the energy level realignment and the change in carrier tunneling probability by the interfacial layer.

  • PDF

ANODICALLY-BONDED INTERFACE OF GLASS TO ALUMINIUM

  • Takahashi, Makoto;Nishikawa, Satoru;Chen, Zheng;Ikeuchi, Kenji
    • Proceedings of the KWS Conference
    • /
    • 2002.10a
    • /
    • pp.65-69
    • /
    • 2002
  • An Al film deposited on the Kovar alloy substrate was anodically-bonded to the borosilicate glass, and the bond interfaces was closely investigated by transmission electron microscopy. Al oxide was found to form a layer ~l0 nm thick at the bond interface, and fibrous structure of the same oxide was found to grow epitaxially in the glass from the oxide layer. The fibrous structure grew with the bonding time. The mechanism of the formation of this fibrous structure is proposed on the basis of the migration of Al ions under the electric field. Penetration of Al into glass beyond the interfacial Al oxide was not detected. The comparison of the amount of excess oxygen ions generated in the alkali depletion layer with that incorporated in the Al oxide suggests that the growth of the alkali-ion depletion layer is controlled by the consumption of excess oxygen to form the interfacial Al oxide.

  • PDF

Effect of the LiF anode interfacial layer on polymer light emitting diodes

  • Sohn, Sun-Young;Lee, Dae-Woo;Park, Keun-Hee;Jung, Dong-Geun;Kim, H.M.;Manna, U.;Yi, J.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2005.07b
    • /
    • pp.1056-1058
    • /
    • 2005
  • Electrical and optical characteristics of MEH-PPV-based PLEDs with the LiF anode interfacial layer were investigated. The maximum luminance efficiency of the device with a LiF anode interfacial layer of 1-nm-thick was 3.0 lm/W, which is higher than 1.97 lm/W of the device without a LiF layer. By inserting LiF, excess injected holes from ITO anode can be blocked and hence the recombination ratio of electrons and holes can be increased in the emitting layer to improve device efficiency.

  • PDF

Improvement of electroluminescent efficiency by using interfacial exciton blocking layer in blue emitting electrophosphorescent organic light emitting diodes

  • Kim, Ji-Whan;Kim, Joo-Hyun;Yoon, Do-Yeung;Kim, Jang-Joo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2005.07b
    • /
    • pp.1381-1382
    • /
    • 2005
  • We report improved efficiency in blue electrophosphorescent organic light emitting diodes by introducing an interfacial exciton blocking layer between light emitting layer (EML) and hole transport layer (HTL). Iridium(III) bis [(4,6-di-fluorophenyl)- pyridinato -N,C2']picolinate (FIrpic) was used as blue phosphorescent dopant and JHK6-3 with carbazole and electron transporting group as host and also as the interfacial layer, resulting in drastic increase in quantum efficiency.

  • PDF

Modelling of Grain Boundary in Polysilicon Film for Photodetector Through Current-Voltage Analysis (광검출기용 다결정 실리콘 박막의 전도특성 분석을 통한 결정립계의 모형화)

  • Lee, Jae-Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.33 no.4
    • /
    • pp.255-262
    • /
    • 2020
  • Grain boundaries play a major role in determining device performance, particularly of polysilicon-based photodetectors. Through the post-annealing of as-deposited polysilicon and then, the analysis of electric behavior for a metal-polysilicon-metal (MSM) photodetector, we were able to identify the influence of grain boundaries. A modified model of polysilicon grain boundaries in the MSM structure is presented, which uses a crystalline-interfacial layer-SiOx layer- interfacial layer-crystalline system that is similar to the Si-SiO2 system in MOS device. Hydrogen passivation was achieved through a hydrogen ion implantation process and was used to passivate the defects at both interfacial layers. The thin SiOx layer at the grain boundary can enhance the photosensitivity of an MSM photodetector by decreasing the dark current and increasing the light absorption.

Effects of Superheat and Coating Layer on Interfacial Heat Transfer Coefficient between Copper Mold and Aluminum Melt during Solidification (응고중 구리 주형과 알루미늄 용탕의 계면열전달계수에 미치는 용탕과열도와 도형재의 영향)

  • Kim, Hee-Soo;Shin, Je-Sik;Lee, Sang-Mok;Moon, Byung-Moon
    • Journal of Korea Foundry Society
    • /
    • v.24 no.5
    • /
    • pp.281-289
    • /
    • 2004
  • The present study focused on the estimation of the interfacial heat transfer coefficient as a function of the surface temperature of the aluminum casting at the mold/casting interface to investigate the effects of superheat and coating layer. The casting experiments of aluminum into a cylindrical copper mold were systematically conducted to obtain the thermal history during solidification. The thermal history recorded by four thermocouples embedded both in the mold and the casting was used to solve the inverse heat conduction problem using Beck's method. The effects of superheat and coating on the interfacial heat transfer coefficient in the liquid state, during the solidification, and in the solid state were comparatively discussed. In the liquid state, the interfacial heat transfer coefficient is thought to be affected by the roughness of the mold, the wettability of the casting on the mold surface, and the thermophysical properties of the coating layer. When the solidification begins, the air gap forms between the casting and the mold, and the interfacial heat transfer coefficient becomes a function of the air gap as well as surface roughness and the superheat. In the solid phase, it depends only upon the thermal conductivity and the thickness of the air gap. The coating layer reduces seriously the interfacial heat transfer coefficient in the liquid state and during the solidification.