• Title/Summary/Keyword: Single-junction

Search Result 306, Processing Time 0.026 seconds

Measurement of Junction Temperature in High Power LED Module with Property Analysis of Single Package (단일 패키지의 특성 분석을 통한 고출력 발광 다이오드 모듈의 접합 온도 측정)

  • Lee, Se-IL;Kim, Woo-Young;Jeong, Young-Gi;Yang, Jong-Kyung;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.23 no.12
    • /
    • pp.973-977
    • /
    • 2010
  • The temperature of junction in LED affects the life time and performance. however, the measurement of junction temperature in module is very difficult. In this paper, to measure the junction temperature in LED module, optical and electrical properties is measured in single package in temperature from 25 [$^{\circ}C$] to 85 [$^{\circ}C$], and then junction temperature can is estimated in module with measuring the average voltage of single package. As results, the junction temperature of single package is measured the temperature of 61.2 [$^{\circ}C$] in ambient temperature, also, the junction temperature of LED module is measured the temperature of 72.5 [$^{\circ}C$] in ambient temperature.

Oxygen-Silver Junction Formation for Single Molecule Conductance

  • Jo, Han Yeol;Yoo, Pil Sun;Kim, Taekyeong
    • Journal of the Korean Chemical Society
    • /
    • v.59 no.1
    • /
    • pp.18-21
    • /
    • 2015
  • We use a scanning tunneling microscope based break-junction technique to measure the conductance of a 4,4'-dimethoxybiphenyl molecular junction formed with Ag and Au electrodes. We observe the formation of a clear molecular junction with Ag electrodes that result from stable Ag-oxygen bonding structures. However we have no molecular bonding formation when using Au electrodes, resulting in a tunneling current between the top and bottom metal electrodes. We also see a clear peak in the conductance histogram of the Ag-oxygen molecular junctions, but no significant molecular features are seen with Au electrodes. Our work should open a new path to the conductance measurements of single-molecule junctions with oxygen linkers.

A Study on the Stability for Single-Layer Latticed Spherical Dome with Span 300m according to Junction's Condition of Member (스팬 300m 대공간 단층래티스 돔의 부재 접합조건에 따른 안정성 검토에 관한 연구)

  • Jung, Hwan-Mok
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2018.05a
    • /
    • pp.14-15
    • /
    • 2018
  • This study is to estimate the buckling characteristics of single-layer latticed dome with Span 300m according to junction's conditions of member.

  • PDF

Effect of Bundle Junction Face and Misalignment on the Pressure Drops Across a Randomly Loaded and Aligned 12 Bundles in Candu Fuel Channel

  • H. C. Suk;K. S. Sim;C. H. Chung;Lee, Y. O.
    • Nuclear Engineering and Technology
    • /
    • v.28 no.3
    • /
    • pp.280-289
    • /
    • 1996
  • The pressure drop of twelve fuel bundle string in the CANDU-6 fuel channel is equal to the sum of the eleven junction pressure losses, the bundle string entrance and exit pressure losses, the skin friction pressure loss, and other appendage pressure losses, where the junction loss is dependent on the bundle end faces and angular alignments of the junctions. The results of the single junction pressure drop tests in a short rig show that the most probable pressure drop of the eleven junctions was analytically equal to the eleven times of average pressure drop of all the possible single junction pressure drops, and also that the largest and smallest junction pressure drops across the eleven junctions probably occurred only with BA and BB type junctions, respectively, where A and B denote the bundle end sides with an end-plates on which a company monogram is stamped and unstamped, respectively.

  • PDF

Physics and current density-voltage characteristics of $a-Si_{1-x}Ge_x:H$ alloy p-i-n solar cells ($a-Si_{1-x}Ge_x:H$ 화합물(化合物) p-i-n 태양전지(太陽電池)의 물리(物理) 및 전류밀도(電流密度)-전압(電壓) 특성(特性))

  • Kwon, Young-Shik
    • Proceedings of the KIEE Conference
    • /
    • 1994.07b
    • /
    • pp.1435-1438
    • /
    • 1994
  • The effects of Ge composition variation in $a-Si_{1-x}Ge_x:H$ alloy p-i-n solar cells on the physical properties and current density-voltage characteristics are analyzed by a new simulation modelling based on the update published experimental datas. The simulation modelling includes newly formulated density of gap density spectrum corresponding to Ge composition variation and utilizes the newly derived generation rate formulars which include the reflection coefficients and can apply to multijunction structures as well as single junction structure. The effects in $a-Si_{1-x}Ge_x:H$ single junction are analyzed through the efficiency, fill factor, open circuit voltage, short circuit current density, free carriers, trap carriers, electric field, generation rate and recombination rate. Based on the results analyzed in single junction structure, the applications to multiple junction structures are discussed and the optimal conditions reaching to a high performance are investigated.

  • PDF

Conductance Difference of Single Molecular Junctions between Experiments and Computational Simulations

  • Choi, Ji Il;Kim, Hu Sung;Kim, Young-Hoon
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.184.2-184.2
    • /
    • 2014
  • Recent advances in the synthesis and characterization of nanoscale objects provided us with the atomistic understanding of charge transport through single molecular junctions. The representative examples are the mechanically controlled break junction technique and STM or conducting AFM junction techniques. Theoretical studies have been reported on the dependence of electronic charge transport on the geometry of molecule-electrode contacts, the critical element toward the realization of molecular electronics. In this report, we will clarify the puzzling discrepancies between theoretical predictions and experiments.

  • PDF

Conductance of a Single Molecule Junction Formed with Ni, Au, and Ag Electrodes

  • Kim, Taekyeong
    • Journal of the Korean Chemical Society
    • /
    • v.58 no.6
    • /
    • pp.513-516
    • /
    • 2014
  • We measure the conductance of a 4,4'-diaminobiphenyl formed with Ni electrodes using a scanning tunneling microscope-based break-junction technique. For comparison, we use Au or Ag electrodes to form a metal-molecular junction. For molecules that conduct through the highest occupied molecular orbital, junctions formed with Ni show similar conductance as Au and are more conductive than those formed with Ag, consistent with the higher work function for Ni or Au. Furthermore, we observe that the measured molecular junction length that is formed with the Ni or Au electrodes was shorter than that formed with the Ag electrodes. These observations are attributed to a larger gap distance of the Ni or Au electrodes compared to that of the Ag electrodes after the metal contact ruptures. Since our work allows us to measure the conductance of a molecule formed with various electrodes, it should be relevant to molecular electronics with versatile materials.

A Study on Effect of the Junction's Eccentricity for Buckling Characteristics of Single-Layer Latticed Dome (접합부 편심을 고려한 단층 래티스돔의 좌굴특성에 관한 연구)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
    • /
    • v.1 no.1 s.1
    • /
    • pp.117-124
    • /
    • 2001
  • In Single-layer latticed domes with rectangular network which is composed of ring of circumferential direction and rafter of longitudinal direction, that is, rib domes, if we use the cross-membered junction's method for the advantage in fabrication and construction, the eccentricity is occurred in the nodal point of crossing members. This paper is aimed at investigating the buckling characteristics for the effect of eccentricity according to rise-span ratios and distance of eccentricity. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. The maximum decreasing ratio of buckling strength due to the junction's eccentricity is about 60% in models of this paper. 2. In the increasing ratio of buckling strength for rise-span ratio, that of Type 3 models is larger than that of type 2 models. On the other hand, that of Type 2 mode is larger than that of Type 3 for eccentricity-distance. 3. In the viewpoint of the value of buckling strength, that of Type 2 models is larger than that of type 3 models. The effect of the junction's rigidity on buckling strength is not great for overall models. Therefore if we use the cross-membered junction's method for the advantage in fabrication and construction, the method of Type 2 will have the great advantage of that of Type 3.

  • PDF

Determination of Memory Trap Distribution in Charge Trap Type SONOSFET NVSM Cells Using Single Junction Charge Pumping Method (Single Junction Charge Pumping 방법을 이용한 전하 트랩 형 SONOSFET NVSM 셀의 기억 트랩 분포 결정)

  • 양전우;흥순혁;박희정;김선주;서광열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1999.11a
    • /
    • pp.453-456
    • /
    • 1999
  • The Si-SiO$_2$interface trap and nitride bulk trap distribution of SONOSFET(polysilicon-oxide-nitride-oxide-semiconductor)NVSM(nonvolatile semiconductor memory) cell were investigated by single charge pumping method. The used device was fabricated by 0.35 7m standard logic fabrication including the ONO cell process. This ONO dielectric thickness is tunnel oxide 24 $\AA$, nitride 74 $\AA$, blocking oxide 25 $\AA$, respectively. Keeping the pulse base level in accumulation and pulsing the surface into inversion with increasing amplitudes, the charge pumping current flow from the single junction. Using the obtained I$_{cp}$-V$_{h}$ curve, the local V$_{t}$ distribution, doping concentration, lateral interface trap distribution and lateral memory trap distribution were extracted. The maximum N$_{it}$($\chi$) of 1.62$\times$10$^{19}$ /cm$^2$were determined.mined.d.

  • PDF

Determination of Memory Trap Distribution in Charge Trap Type SONOSFET NVSM Cells Using Single Junction Charge Pumping Method (Single Junction Charge Pumping 방법을 이용한 전하 트랩형 SONOSFET NVSM 셀의 기억 트랩분포 결정)

  • 양전우;홍순혁;서광열
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.10
    • /
    • pp.822-827
    • /
    • 2000
  • The Si-SiO$_2$interface trap and nitride bulk trap distribution of SONOSFET(polysilicon-oxide-nitride-oxide-semiconductor field effect transistor) NVSM (nonvolatile semiconductor memory) cell is investigated by single junction charge pumping method. The device was fabricated by 0.35㎛ standard logic fabrication process including the ONO stack dielectrics. The thickness of ONO dielectricis are 24$\AA$ for tunnel oxide, 74 $\AA$ for nitride and 25 $\AA$ for blocking oxide, respectively. By the use of single junction charge pumping method, the lateral profiles of both interface and memory traps can be calculated directly from experimental charge pumping results without complex numerical simulation. The interface traps were almost uniformly distributed over the whole channel region and its maximum value was 7.97$\times$10$\^$10/㎠. The memory traps were uniformly distributed in the nitride layer and its maximum value was 1.04$\times$10$\^$19/㎤. The degradation characteristics of SONOSFET with write/erase cycling also were investigated.

  • PDF