• 제목/요약/키워드: optoelectronic

검색결과 554건 처리시간 0.029초

타원형 공동을 갖는 새로운 고복굴절 광섬유의 설계 (Novel design of higly-birefringet fiber with elliptical hollow)

  • 황인각;이용희;오경환
    • 한국광학회:학술대회논문집
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    • 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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    • pp.370-371
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    • 2004
  • We propose and analyze a novel high-birefringence fiber incorporating an elliptical air hole in the core. Compared to solid elliptical core fibers, several times higher birefringence is achieved with a sub-wavelength-sized hole.

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광대역 교환을 위한 InP JFET소자 (InP JFET Devices for High Speed Switching Application)

  • 지윤규;김성준;정종민
    • 전자공학회논문지A
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    • 제28A권5호
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    • pp.370-374
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    • 1991
  • A high performance fully ion-implanted InP JFET was characterized for high speed switching elements. The switch has an insertion loss of 5.5dB with 31.6dB isolation at 1GHz. This device can effectively swithc a byte-multiplexed 2Gb/s signal and an eye-diagram taken at 2Gb/s shows an error-free eye pattern. Therefore, this device can be used as a switching element for high transmission data rate for monolithic integration of optoelectronic circuit in the long-wavelength region.

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단일칩 마이크로 프로세서로 구현한 연속 차광 감지 시스템의 설계 (Design of Successive Safety Light Curtain System Using Single Chip Microprocessor)

  • 박찬원;이영준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 G
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    • pp.3233-3235
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    • 1999
  • This paper describes development of a microprocessor-based optoelectronic guard system established a higher level of control reliability in machine guard design. The system uses the design concept of diverse redundancy and a fast software algorithm. We have accomplished an safety light curtain system that allows to be intentionally disabled moving machine by the interrupt of dangerous situations. As a result, it is showed that the proposed system is effective enough to practical applications.

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Review of Low-Dimensional Nanomaterials for Blue-Light Emission

  • Won Kook Choi
    • 센서학회지
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    • 제32권6호
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    • pp.391-402
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    • 2023
  • Low-dimensional (zero-dimensional (0-dim), 2-dimensional (2-dim)) nanoparticles, such as chalcogenide compound semiconductors, III-V semiconductors, transition metal dichalcogenides (TMDs), II-VI semiconductors, nanocarbons, hybrid quantum dots (QDs), and perovskite QDs (PQDs), for which blue light emission has been observed, are reviewed. Current synthesis and device fabrication technologies as well as their prospective applications on next-generation quantum-dot-based light-emitting diodes are discussed.

Energy separation and carrier-phonon scattering in CdZnTe/ZnTe quantum dots on Si substrate

  • 만민탄;이홍석
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.191.2-191.2
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    • 2015
  • Details of carrier dynamics in self-assembled quantum dots (QDs) with a particular attention to nonradiative processes are not only interesting for fundamental physics, but it is also relevant to performance of optoelectronic devices and the exploitation of nanocrystals in practical applications. In general, the possible processes in such systems can be considered as radiative relaxation, carrier transfer between dots of different dimensions, Auger nonradiactive scattering, thermal escape from the dot, and trapping in surface and/or defects states. Authors of recent studies have proposed a mechanism for the carrier dynamics of time-resolved photoluminescence CdTe (a type II-VI QDs) systems. This mechanism involves the activation of phonons mediated by electron-phonon interactions. Confinement of both electrons and holes is strongly dependent on the thermal escape process, which can include multi-longitudinal optical phonon absorption resulting from carriers trapped in QD surface defects. Furthermore, the discrete quantized energies in the QD density of states (1S, 2S, 1P, etc.) arise mainly from ${\delta}$-functions in the QDs, which are related to different orbitals. Multiple discrete transitions between well separated energy states may play a critical role in carrier dynamics at low temperature when the thermal escape processes is not available. The decay time in QD structures slightly increases with temperature due to the redistribution of the QDs into discrete levels. Among II-VI QDs, wide-gap CdZnTe QD structures characterized by large excitonic binding energies are of great interest because of their potential use in optoelectronic devices that operate in the green spectral range. Furthermore, CdZnTe layers have emerged as excellent candidates for possible fabrication of ferroelectric non-volatile flash memory. In this study, we investigated the optical properties of CdZnTe/ZnTe QDs on Si substrate grown using molecular beam epitaxy. Time-resolved and temperature-dependent PL measurements were carried out in order to investigate the temperature-dependent carrier dynamics and the activation energy of CdZnTe/ZnTe QDs on Si substrate.

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직접천이 띠간격을 갖는 $Ge_{1-x}$$Sn_x$/$Ge_{1-y}$$Sn_y$(001)의 전기적 특성 연구 (Study of the electrical propety for $Ge_{1-x}$$Sn_x$/$Ge_{1-y}$$Sn_y$((001) with a direct gap)

  • 박일수;전상국
    • 한국전기전자재료학회논문지
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    • 제13권12호
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    • pp.989-995
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    • 2000
  • G $e_{1-x}$ S $n_{x}$G $e_{1-y}$S $n_{y}$ is a very promising material for the high-speed device due to the fact that electron and hole mobilities for the strained G $e_{1-x}$ S $n_{x}$G $e_{1-y}$S $n_{y}$ are greatly enhanced. Because G $e_{1-x}$ S $n_{x}$G $e_{1-y}$S $n_{y}$ has a direct band gap for the proper combination of x and y, it can be applied to the optoelectronic device. Therefore, the study of the electrical property for G $e_{1-x}$ S $n_{x}$G $e_{1-y}$S $n_{y}$(001) with a direct energy gap is needed. G $e_{1-x}$ S $n_{x}$ layer can not be grown thickly due to the large difference of lattice constants. This fact prefers the structure of the device where electrons and holes move in the plane direction. The transverse mobilities of electron and hole for G $e_{0.8}$S $n_{0.2}$Ge(001) are 2~3 times larger than those for Ge/Ge/ sub0.8/S $n_{0.2}$(001). Therefore, G $e_{0.8}$S $n_{0.2}$Ge(001) is expected to be better than Ge/G $e_{0.8}$S $n_{0.2}$(001) for the development of the high-speed device.h-speed device.device.h-speed device. device.

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광전소자 패키징에서 광섬유 정렬을 위한 Si V-groove 형성 (The formation of Si V-groove for optical fiber alignment in optoelectronic devices)

  • 유영석;김영호
    • 마이크로전자및패키징학회지
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    • 제6권3호
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    • pp.65-71
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    • 1999
  • 광 패키징에서 광섬유와 광전자소자를 정확히 정렬하기 위한 V-groove의 치수 정밀도에 미치는 마스크 재료와 에칭용액의 영향을 연구하였다. PECVD nitride, LPCVD nitride, thermal oxide($SiO_2$)를 마스크재료로 사용하였고 실리콘을 이방성에칭하는 용액으로 KOH(40wt%)용액과 KOH(40wt%)용액에 IPA를 첨가한 용액을 이용하였다. 마스크재료로는 LPCVD nitride가 가장 좋은 선택적에칭특성을 나타내었으며 사용된 마스크재료 중 thermal oxide가 가장 빠른 속도로 에칭되었다. V-groove의 크기 증가는 마스크충 아래로의 undercutting에 의해 생겼는데 이는 주로 (111)면으로의 에칭 때문이었다. KOH(40wt%)용액에서 (111)면의 에칭속도는 0.034 - 0.037 $\mu\textrm{m}$/min로 마스크재료에 관계없이 거의 일정하였다. IPA를 KOH(40wt%)용액에 첨가하면 (100)면과 (111)면의 에칭속도는 모두 감소하지만 (111)면에 대한 (100)면의 에칭속도비는 증가하였다. 그러므로 이런 용액에서 (111)면으로의 에칭에 의한 undercutting현상은 줄어들었으며 V-groove의 크기를 더 정확하게 조절할 수 있었다.

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실리콘 기판위에서의 Cr-Doped SrZrO3 박막의 저항변화 특성 (Resistive Switching Properties of Cr-Doped SrZrO3 Thin Film on Si Substrate)

  • 양민규;고태국;박재완;이전국
    • 한국재료학회지
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    • 제20권5호
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    • pp.241-245
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    • 2010
  • One of the weak points of the Cr-doped SZO is that until now, it has only been fabricated on perovskite substrates, whereas NiO-ReRAM devices have already been deposited on Si substrates. The fabrication of RAM devices on Si substrates is important for commercialization because conventional electronics are based mainly on silicon materials. Cr-doped ReRAM will find a wide range of applications in embedded systems or conventional memory device manufacturing processes if it can be fabricated on Si substrates. For application of the commercial memory device, Cr-doped $SrZrO_3$ perovskite thin films were deposited on a $SrRuO_3$ bottom electrode/Si(100)substrate using pulsed laser deposition. XRD peaks corresponding to the (112), (004) and (132) planes of both the SZO and SRO were observed with the highest intensity along the (112) direction. The positions of the SZO grains matched those of the SRO grains. A well-controlled interface between the $SrZrO_3$:Cr perovskite and the $SrRuO_3$ bottom electrode were fabricated, so that good resistive switching behavior was observed with an on/off ratio higher than $10^2$. A pulse test showed the switching behavior of the Pt/$SrZrO_3:Cr/SrRuO^3$ device under a pulse of 10 kHz for $10^4$ cycles. The resistive switching memory devices made of the Cr-doped $SrZrO_3$ thin films deposited on Si substrates are expected to be more compatible with conventional Si-based electronics.