• Electrical & Electronic Materials
• /
• v.9 no.2
• /
• pp.174-179
• /
• 1996

We present a new physically based analytical equation for electron effective mobility in MOS inversion layers. The new semi-empirical model is accounting expicitly for surface roughness scattering and screened Coulomb scattering in addition to phonon scattering. This model shows excellent agreement with experimentally measured effective mobility data from three different published sources for a wide range of effective transverse field, channel doping and temperature. By accounting for screened Coulomb scattering due to doping impurities in the channel, our model describes very well the roll-off of effective mobility in the low field (threshold) region for a wide range of channel doping level (Na=3.0*10$^{14}$ - 2.8*10$^{18}$ cm$^{-3}$ ).

• Journal of Sensor Science and Technology
• /
• v.5 no.2
• /
• pp.55-60
• /
• 1996

The growth and microwave plasma assisted nitrogen doping of ZnSe by low pressure organometallic vapor phase epitaxy(OMVPE) has been investigated in a vertical downflow reactor equipped with a laser interferometer for in-situ growth rate measurements. Particular emphasis is placed on understanding growth characteristics of $H_{2}Se$ and the new adduct source dimethylzinc:triethyllamine($DMZn:NEt_{3}$) as compared with those obtained with $H_{2}Se$ and DMZn. At lower temperatures ($<300^{\circ}C$) and pressures(<30Torr), growth rates are higher with the adduct source and the surface morphology is improved relative to films synthesized with DMZn. Hall measurements and photoluminescence spectra of the grown films demonstrate that DMZn and $DMZn:NEt_{3}$ produce material with comparable electronic and optical properties. Microwave plasma decomposition of ammonia is investigated as a possible approach to increasing nitrogen incorporation in ZnSe and photoluminescence spectra are compared to those realized with conventional ammonia doping.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.10a
• /
• pp.31.1-31.1
• /
• 2011

$Li_4Ti_5O_{12}$ is emerging as a promising material with its good structure stability and little volume change during the electrochemical reaction. However, its electrochemical performance is significantly limited by low electronic or ionic conductivity. In addition, high tap density is needed forim proving its volumetric energy density and commercialization. To enhance these properties, the spherical-like $Li_4Ti_5O_{12}$ particles were synthesized and carried out doping with yttrium. Prepared Y-doped $Li_4Ti_5O_{12}$ as a anode material showed great capacity retention rate of 92% (5C/0.2C), compared with no dope done. Consequently, it was found that Y doping into $Li_4Ti_5O_{12}$ matrix reduces the polarization and resistance on SEI layer during the electrochemical reaction.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.7
• /
• pp.2199-2202
• /
• 2011

The electronic properties of altretamine(2,4,6-tris [dimethylamino]-1,3,5-triazine) adsorbed on epitaxial graphene (EG) were investigated by core-level photoemission spectroscopy (CLPES) in conjunction with low energy electron diffraction (LEED). We found that altretamine molecule adsorbed onto interface layer (S1) of graphene as we confirm decrement of S1 peak using CLPES and haziness of LEED pattern. Moreover, the measured work function changes verified that increased adsorption of the altretamine on graphene layer showed n-type doping characteristics due to charge transfer from altretamine to graphene through the nitrogens. Two distinct nitrogen bonding feature associated with the N 1s peak was clearly observed in the core-level spectra indicating two different chemical environments.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.393-393
• /
• 2011

오늘 날 태양전지 산업에서 가장 많은 생산을 하고 있는 분야는 결정질 태양전지분야이다. 현재는 이러한 시대적 요구에 따라 많은 연구가 진행되고 있는데 특히 junction을 이루는 n layer의 doping profile을 선택적으로 형성하여 개방전압 및 단락전류를 향상시키는 연구가 활발히 진행되고 있다. 본 연구는 이러한 n type layer의 doping profile을 선택적으로 형성하는 selective emitter solar cell에 관한 연구로써 SILVACO simulation을 이용하여 low Rs 영역은 고정하고 high Rs 영역의 doping depth를 가변 함으로써 high Rs 영역을 달리 형성하는 방법으로 selective emitter solar cell의 high Rs영역의 최적화에 관한 전산모사를 실시하였다. 각각의 가변조건에 따라 quantum efficiency를 통한 광학적 분석과 I-V를 통한 전기적 분석을 하여 high Rs영역을 최적화 하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.87-90
• /
• 2007

VIATRON TECHNOLOGIES has developed an $\underline{A}$tmospheric $\underline{M}$etal $\underline{D}$oping (AMD) system which uniformly dopes metal species onto a substrate. The AMD system injects metal-organic vapor over substrate using an injection head with a scan motion. One of important application of this system is a metalinduced crystallization of amorphous Si for manufacturing AMOLED poly-Si panels. The AMD system with a use of Ni vapor source produces doping of trace amount of Ni onto amorphous Si, enabling uniform MIC crystallization. Also, the operation without vacuum condition offers advantages such as easy maintenance, low cost production, and large glass processes.

• Journal of the Korean Ceramic Society
• /
• v.37 no.1
• /
• pp.33-43
• /
• 2000

Up-conversion of rare-earth element added glass is promising area for short wavelength laser source by utilizing high power semiconductor infra-red laser if the efficiency can be increased by proper method. In this study, relatively low phonon energy fluoride glasses were prepared by co-doping rare-earth elements to realize the high efficiency up-convertor. The physical, chemical, andoptical properties of co-doped fluoride glasses were measured. 10 combinations of 5 different rare-earth fluoride elements doped samples were prepared and their transition temperatures, chemical durability, density, hardness, refractive index, absorption, fluorescence, and fluorescence lifetime were measured. 480nm wavelengths blue up-conversion was found in the Yb3+/Tm3+ co-doped glass sample with 800nm laser source and the optimum composition for the most efficient blue up-conversion was found from the glass sample with 0.3 mol% TmF3 and 1 mol% YbF3.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.436-439
• /
• 2000

Change of dielectric loss of use in high relative permitivity capacitor BaTiO$_3$ ceramic depends on Mn doping have been investigated. The powders used in this study were commercial BaTiO$_3$, TiO$_2$and, MnCO$_3$. Sample was fabricated by conventional ceramic process. The quantity of Mn was changed gradually from 0.lmol% to 10mo1%. The sintering densities were reduced with increasing amount of MnCO$_3$. This result is because of increase of low density second phase BaMnO$_3$. When the samples were doped by over 0.2mol% of MnCO$_3$, average grain sizes were enlarge to several tens ${\mu}{\textrm}{m}$. The dielectric losses were reduced by Mn doping to lmol% but, increased from lmol% to 10mo1% gradually.

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.3-5
• /
• 2002

Breakdown characteristics of a punch-through diode with n+p+p-n+ structure are analyzed with two-dimensional device simulation. Effects of base doping concentration and profile on the breakdown are presented. An analytical expression of a maximum base doping level for the punch-through breakdown is derived. The diode with a linearly graded base doping shows superior leakage current and capacitance is satisfactory for applications for low-voltage circuits.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.140-141
• /
• 2006

Background doping concentration (BDC) is proven to be a critical factor to affect the high current behavior of the extended drain NMOSFET (EDNMOS) devices. The EDNMOS device with low BDC suffers from strong snapback in the high current region, which results in poor electrostatic discharge (ESD) protection performance and high latchup risk. However, the strong snapback can be avoided in the EDNMOS device with high BDC. This implies that both the good ESD protection performance and the latchup immunity can be realized in terms of the EDNMOS by properly controlling its BDC.