• 한국재료학회지
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• 제24권3호
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• pp.140-144
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• 2014

The contact mechanism of devices is usually researched at electrode contacts. However, the contact between a dielectric and channel at the MOS structure is more important. The graphene was used as a channel material, and the thin film transistor with MOS structure was prepared to observe the contact mechanism. The graphene was obtained on Cu foil by the thermal decomposition method with $H_2$ and $CH_4$ mixed gases at an ambient annealing temperature of $1000^{\circ}C$ during the deposition for 30 min, and was then transferred onto a $SiO_2/Si$ substrate. The graphene was doped in a nitrogen acidic solution. The chemical properties of graphene were investigated to research the effect of nitric atoms doping. The sheet resistance of graphene decreased after nitrogen acidic doping, and the sheet resistance decreased with an increase in the doping times because of the increment of negative charge carriers. The nitric-atom-doped graphene showed the Ohmic contact at the curve of the drain current and drain voltage, in spite of the Schottky contact of grapnene without doping.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.350-354
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• 2018

Lifetime study of blue phosphorescent and thermally activated delayed fluorescent organic light-emitting diodes was carried out to understand the dominant degradation process during electrical operation of the devices. Doping concentration dependence of the phosphorescent and thermally activated delayed fluorescent organic light-emitting diodes was studied, which demonstrated long lifetime at low doping concentration in the phosphorescent devices and at high doping concentration in the thermally activated delayed fluorescent devices. Detailed mechanism study of the two devices described that triplet-triplet annihilation is the main degradation process of phosphorescent organic light-emitting diodes, whereas triplet-polaron annihilation is the key degradation factor of the thermally activated delayed fluorescent devices.

• The Korean Journal of Ceramics
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• 제5권1호
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• pp.40-43
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• 1999

In order to investigate Sn substitution sites and interstitial O atoms in tin-doped indium oxide, molecular dynamics (MD) simulations were carried out. There are two kinds of cation sites in $In_2O_3$, namely b-site and d-site. NTP-MD simulations under the condition of 300 K and 0 GPa were performed with two kinds of cells substituted by Sn atoms at each site. The excess oxygen atom accompanied with Sn doping was also taken into consideration. According to the calculations of Sn potential energies in each site, it was revealed that Sn atoms were substituted for b-sites rather than for d-sites. It was also revealed that the interstitial excess oxygen atoms tend to be connected with the Sn atoms substituted for the d-sites Sn rather than for the b-site. There MD simulation results well agreed with the experimental results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.5-5
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• 2008

We design and demonstrate the controled doping into ZnO nanowires (NWs) adopting self-contrived hot-walled pulsed laser deposition (HW-PLD). Optimized synthesis conditions with the diversified dopants guarantee the excellent crystalinity and morphology as well as electrical properties of the NWs. Proprietary target rotating system in the HW-PLD fuels the controlled formation and doping of the NWs. Prepared NWs sensitive to the environment are systematically characterized, and the doping mechanism is discussed.

• 마이크로전자및패키징학회지
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• 제24권2호
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• pp.49-53
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• 2017

Cl 불순물 도핑에 따른 $SnSe_2$ 이차원 전자소재의 고온(300~450 K) 전도 물성 변화를 고찰하였다. 고상합성법을 통하여, 도핑이 없는 $SnSe_2$ 소재와 Cl이 도핑된 $SnSe_{1.994}Cl_{0.006}$ 소재를 합성하였으며, X선 회절 실험을 통하여, 두 재료 모두 불순물 없는 단일상이 형성되었음을 확인하였다. 비저항의 온도의존성 측정을 통하여, 전기 전도 mechanism이 Cl 도핑에 의해 hopping 전도에서 축퇴 전도로의 전이가 일어남을 관찰할 수 있었으며, 홀효과 측정을 통해 그러한 전도 mechanism의 전이가, Cl의 효과적인 donor 역할에 따른 자유전자의 농도 증가에서 기인한 것임을 확인하였다. 온도에 따른 전자이동도의 변화 분석을 통하여, 도핑이 없는 $SnSe_2$의 고온 전기 전도는 grain boundary 산란이 지배적인 영향을 미치는 반도체 전도 특성을 보이는 반면, Cl 도핑에 따라 grain boundary 산란 효과가 저하되는 금속 전도 특성을 보인다는 것을 알 수 있었다.

• E2M - 전기 전자와 첨단 소재
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• 제9권2호
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• pp.165-173
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• 1996

We prepared polythiophene and poly(3-methylthiophene) films, known as conducting polymer, by electrochemical method. Polythiophene and poly(3-methylthiophene) films were doped and undoped dopant for the studing the understanding of doping mechanism and possible application to the color change switch. We observed that the anodic, cathodic wave and absorption spectra were slightly changed during doping and undoping process in polythiophene. It shows that doping and undoping process were showed some difference by the appearance and disappearance of polaron and bi-polaron. In the relation of the peak of oxidative current density and potential sweep rate of cyclic voltammograms, the amount of dopant in polythiophene film was homogeneously increased at low scan rate. This also can be applied to the poly(3-methlythiophene).

• Macromolecular Research
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• 제17권9호
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• pp.631-637
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• 2009

This study examined the unique self-doping behavior of carboxylated polyaniline (PCA). The self-doped PCA was synthesized using an environmentally benign enzymatic polymerization method with cationic surfactants. XPS showed that HCl-doped PCA contained approximately 34% of protonated amines but self-doped PCA contained 9.6% of the doped form of nitrogen at pH 4. FTIR and elemental analysis showed that although the PCA was doped with the proton of strong acids at low pH via the protonation of amines, the self-doping mechanism of PCA at pH > 4 was mainly due to hydrogen bonding between the carboxylic acid group and amine group.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 춘계 학술대회
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• pp.173-179
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• 2005

본 연구에서는 Nickel-Metal Induced Lateral crystallization(Ni-MILC)에 depart에 따른 영향을 관찰함에 있어 Nickel에 Palladium Metal을 인접시켜(Pd assisted Ni-MILC) 그 결정화 속도를 향상시키는 방법을 제안하였다. a-Si에 Phosphorous가 doping 되어 있는 경우 Ni-MILC의 성장은 intrinsic에 비해 2.5배 감소되는 반면, Boron을 doping한 경우 Ni-MILC의 성장은 intrinsic의 경우보다 5배 이상의 성장을 보이게 되는데, well type의 Pd을 인접시킨 경우 Pd에 의해 유도된 tensile stress가 각 doping에 따른 성장 속도를 더욱 증대시키는 것을 확인할 수 있었으며, 이와 같은 현상을 MILC mechanism으로 설명하였다. 이는 Ni-MILC를 이용하여 다결정 실리콘 TFT 제작 시 결정화 속도로 인하여 문제가 되었던 N-type에서의 적용이 가능함과 동시에 contact MILC 등의 방법에도 이용가능성을 의미한다.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3319-3325
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• 2014

Eu(III)-doped $CeO_2$ nanorods were prepared by a co-precipitation method at room temperature, and their photoluminescence profiles were examined with different Eu(III)-doping concentrations and thermal annealing temperatures. Scanning electron microscopy, X-ray diffraction crystallography and UV-Vis absorption spectroscopy were employed to examine the morphology, crystal structure and photon absorption profiles of the nanorods, respectively. Additionally, their 2D and 3D-photoluminescence profile maps were obtained to fully understand the photoluminescence mechanism. We found that the magnetic dipole $^5D_0{\rightarrow}^7F_1$ and the electric dipole $^5D_0{\rightarrow}^7F_2$ transitions of Eu(III) were highly dependent on the doping concentration, annealing temperature and excitation wavelength, which was explained by the presence of different Eu(III)-doping sites (with and without an inversion center) in the $CeO_2$ host with a cubic crystal structure.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.328.2-328.2
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• 2014

Semiconductor nanowires (NWs) have attracted research interests due to the distinct physical properties that can lead to variousoptical and electrical applications. In this paper, we have grown InAs NWs viagold (Au)-assisted vapor-liquid-solid (VLS) and catalyst-free vapor-solid (VS) mechanisms and investigated on the p-type doping profile of the NWs. Metal-organic chemical vapor deposition (MOCVD) is used for the growth of the NWs. Trimethylindium (TMIn) and arsine (AsH3) were used for the precursor and diethyl zinc (DEZn) was used for the p-type doping source of the NWs. The effectiveness of p-type doping was confirmed by electrical measurement, showing an increase of the electron density with the DEZn flow. The structural properties of the InAs NWs were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, we characterize atomic distribution of InAs NWs using energy-dispersive X-ray spectroscopy (EDX) analysis.