Kimoon Lee
연세대학교 Materials Science and Engineering · 공학
김운림 교수의 연구실은 주로 산화간이질화물 기반 투명 반도체 소자, 특히 아연산화물(ZnO) 기반 박막트랜지스터(TFT)의 소자 구조 최적화와 물성 분석을 핵심으로 합니다. 고성능 TFT를 구현하기 위해 이중층 게이트 산화막(고k/고분자)과 광자 자극을 이용한 트랩 상태 밀도 정량 측정 기법을 개발하며, 전자기기용 유연하고 저전압 동작 가능한 투명 전자소자를 목표로 하고 있습니다. 또한, 반도체의 원자 도핑과 전자적 특성 변화를 연구함으로써 신소재 기반의 차세대 전자소자 응용을 모색하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A History of the Korean Language is the first book on the subject ever published in English. It traces the origin, formation, and various historical stages through which the language has passed, from Old Korean through to the present day. Each chapter begins with an account of the historical and cultural background. A comprehensive list of the literature of each period is then provided and the textual record described, along with the script or scripts used to write it. Finally, each stage of the
Direct quantitative mapping of the density-of-states, named the photo-excited charge-collection technique, for the interface traps at the n-ZnO and/or p-pentacene thin-film transistor channel is implemented by using monochromatic photons which are carried by optical fibers and are probed onto thin-film transistors.
The authors report on the fabrication of a low-voltage-driven top-gate ZnO thin-film transistor with a polymer/high-k oxide double-layer dielectric. Hybrid double-layer dielectric (k=∼9.8) was formed on patterned ZnO through sequential deposition processes: spin casting of 45-nm-thin poly-4-vinylphenol and e-beam evaporation of 50-nm-thick amorphous high-k oxide (CeO2–SiO2 mixture). Room-temperature-deposited ZnO channel exhibits much rougher surfaces compared to that of 100°C deposited ZnO, so
We report on the fabrication and application of top-gate ZnO thin-film transistors (TFTs) with a poly-4-vinylphenol (PVP) gate dielectric layer formed on n-ZnO by spin casting. Al, Au, and NiOx top-gate metals patterned on the PVP of a top-gate TFT by thermal evaporation exhibited different threshold voltages (Vt) and saturation currents. This provides us with an all-electrical way to measure the work function of an unknown new electrode (NiOx) based on those of two reference electrodes (Al and
We report on photo-excited trap-charge-collection spectroscopy, contrived to measure the density of deep-level traps near channel/dielectric interface in a working ZnO based thin-film transistor as a function of photon probe energy. Free charges trapped at a certain energy level are liberated by the correspondingly energetic photons and then electrically collected at the source/drain electrodes. During this photo-electric process, the threshold voltage of TFT shifts and its magnitude provides th
Discoveries of two-dimensional (2D) magnetism originated from confined atomic layers in van der Waals (vdW) crystals provide an interesting arena for elucidating its fundamentals and enrich magneto-electric and quantum properties. However, a material that exhibits intrinsic 2D magnetism of interstitial electrons occupying layered space, as a root system of magnetic vdW crystals, remains obscure. In this work, 2D ferromagnetic vdW electride, [RECl]2+·2e− (RE = Y and La) is reported with perfectly
Abstract Substitutional atomic doping is one of the most convenient and precise routes to modulate semiconducting material properties. Although two‐dimensional (2D) layered transition metal dichalcogenides (TMDs) are of great interest as a prominent semiconducting material due to their unique physical/chemical properties, such a practical atomic doping is still rare, possibly due to the intrinsic localization nature of conduction paths based on d‐band states. Here, using single‐crystalline Cl‐do
We report on the fabrication of ZnO-based depletion-load-type inverter composed of two n-channel ZnO thin-film transistors (TFTs) with a low-k poly-4-vinylphenol and high-k poly(vinylidene fluoride-trifluoroethylene) double polymer dielectric. One of the two ZnO channels in the inverter was illuminated by 352 nm wavelength ultraviolet so that the illuminated ZnO channel might be depleted. That ZnO-TFT plays as a driver transistor in the inverter set where the original TFT is used as a load one.
We report the origin of improved hole conduction without band-gap collapse in Cu-doped NiO.
Improved dynamic properties of ZnO-based photo-transistor with polymer gate dielectric by ultraviolet treatment, Lee, Kimoon, Kim, Ki-tae, Choi, Jeong-M, Oh, Min Suk, Hwang, D K, Jang, Sungjin, Kim, Eugene, Im, Seongil
Interlayer coupling between individual unit layers is known to be critical in manipulating the layer-dependent properties of two-dimensional (2D) materials. While recent studies have revealed that several 2D materials with significant degrees of interlayer interaction (such as black phosphorus) show strongly layer-dependent properties, the origin based on the electronic structure is drawing intensive attention along with 2D materials exploration. Here, the direct observation of a highly dispersi