http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Doo-Hyeb Youn,Hyun-Tak Kim,Kang-Yong Kang 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.1
The doping concentration and channel thickness dependencies of the current-voltage characteristics in slightly Be-doped GaAs device are investigated. Abrupt metallic transitions occurred in the slightly Be-doped GaAs below np = 5 × 1014 cm−3 and the very thin GaAs channel below 0.3 μm. An abrupt current-jump and negative differential resistance (NDR), have been observed for slightly Be-doped GaAs channels, but have not been observed for the conventional InGaAs avalanche photodiode (APD). With increasing temperatures, the turn-on voltage of current-jump V(ds) decreases for the GaAs device, but increases for the conventional InGaAs APD device.
Li, Lijun,Lee, Inyeal,Youn, Doo-Hyeb,Kim, Gil-Ho IOP Pub 2017 Nanotechnology Vol.28 No.7
<P>We investigate the hopping conduction and random telegraph signal caused by various species of interface charge scatterers in a MoS<SUB>2</SUB> multilayer field-effect transistor. The temperature dependence of the channel resistivity shows that at low temperatures and low carrier densities the carrier transport is via Mott variable range hopping with a hopping length changing from 41 to 80 nm. The hopping conduction was due to electron tunneling through localized band tail states formed by the scatterers located in the vicinity of the MoS<SUB>2</SUB> layer. In the temperature range of 40–70 K, we observed random telegraph signal (RTS) that is caused by the capture and emission of a carrier by the interface traps that are located away from the layer. These traps form strong potential that interact with the layer and change the potential profile of the electron system. The characteristics of RTS depend strongly on gate bias and temperature, as well as the application of a magnetic field.</P>
Chang-Sub Kim,Ji-Hee Kim,이기주,Doo-Hyeb Youn,Kwang-Yong Kang 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.2
The annealing temperature dependence of the carrier dynamics was studied for a GaAs layer grown at 290℃ by using molecular beam epitaxy. The modified carrier lifetime is interpreted to be a result of the increased defect-to-defect distance caused by the aggregation process of As-related point defects. The disappearance of the plasmon-phonon coupling and the carrier-induced phonon dephasing, which are observed in coherent phonon experiments for the layer annealed at 400℃, is consistent with the instantaneous trapping of photoexcited carriers as, observed in pump-probe measurements. The annealing temperature dependence of the carrier dynamics was studied for a GaAs layer grown at 290℃ by using molecular beam epitaxy. The modified carrier lifetime is interpreted to be a result of the increased defect-to-defect distance caused by the aggregation process of As-related point defects. The disappearance of the plasmon-phonon coupling and the carrier-induced phonon dephasing, which are observed in coherent phonon experiments for the layer annealed at 400℃, is consistent with the instantaneous trapping of photoexcited carriers as, observed in pump-probe measurements.
Fabrication and Characterization of an OTFT-Based Biosensor Using a Biotinylated F8T2 Polymer
Sang Chul Lim,양용석,Seong Hyun Kim,Zin-Sig Kim,Doo-Hyeb Youn,Taehyoung Zyung,Ji Young Kwon,황도훈,김도진 한국전자통신연구원 2009 ETRI Journal Vol.31 No.6
Solution-processable organic semiconductors have been investigated not only for flexible and large-area electronics but also in the field of biotechnology. In this paper, we report the design and fabrication of biosensors based on completely organic thin-film transistors (OTFTs). The active material of the OTFTs is poly(9,9-dioctylfluorene-co-bithiophene) (F8T2) polymer functionalized with biotin hydrazide. The relationship between the chemoresistive change and the binding of avidin-biotin moieties in the polymer is observed in the output and on/off characteristics of the OTFTs. The exposure of the OTFTs to avidin causes a lowering of ID at VD = -40 V and VG = -40 V of nearly five orders of magnitude.
Khan, Muhammad Atif,Rathi, Servin,Lee, Changhee,Lim, Dongsuk,Kim, Yunseob,Yun, Sun Jin,Youn, Doo-Hyeb,Kim, Gil-Ho American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.28
<P>Two-dimensional (2D) material-based heterostructures provide a unique platform where interactions between stacked 2D layers can enhance the electrical and opto-electrical properties as well as give rise to interesting new phenomena. Here, the operation of a van der Waals heterostructure device comprising of vertically stacked bilayer MoS<SUB>2</SUB> and few layered WSe<SUB>2</SUB> has been demonstrated in which an atomically thin MoS<SUB>2</SUB> layer has been employed as a tunneling layer to the underlying WSe<SUB>2</SUB> layer. In this way, simultaneous contacts to both MoS<SUB>2</SUB> and WSe<SUB>2</SUB> 2D layers have been established by forming a direct metal-semiconductor to MoS<SUB>2</SUB> and a tunneling-based metal-insulator-semiconductor contacts to WSe<SUB>2</SUB>, respectively. The use of MoS<SUB>2</SUB> as a dielectric tunneling layer results in an improved contact resistance (80 kΩ μm) for WSe<SUB>2</SUB> contact, which is attributed to reduction in the effective Schottky barrier height and is also confirmed from the temperature-dependent measurement. Furthermore, this unique contact engineering and type-II band alignment between MoS<SUB>2</SUB> and WSe<SUB>2</SUB> enables a selective and independent carrier transport across the respective layers. This contact engineered dual channel heterostructure exhibits an excellent gate control and both channel current and carrier types can be modulated by the vertical electric field of the gate electrode, which is also reflected in the on/off ratio of 10<SUP>4</SUP> for both electron (MoS<SUB>2</SUB>) and hole (WSe<SUB>2</SUB>) channels. Moreover, the charge transfer at the heterointerface is studied quantitatively from the shift in the threshold voltage of the pristine MoS<SUB>2</SUB> and the heterostructure device, which agrees with the carrier recombination-induced optical quenching as observed in the Raman spectra of the pristine and heterostructure layers. This observation of dual channel ambipolar transport enabled by the hybrid tunneling contacts and strong interlayer coupling can be utilized for high-performance opto-electrical devices and applications.</P> [FIG OMISSION]</BR>