• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1635-1636
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• 2006

In this paper, a non-vacuum packaged single crystalline silicon MEMS gyroscope is designed, fabricated and tested. To reduce air damping of the gyroscope structure for non-vacuum packaging, air damping model is used and damping is minimized by analysis. The inner and outer spring length is optimized by ANSYS simulation for rigid body motion. The gyroscope is fabricated by SiOG(Silicon On Glass) process. The performance of the gyroscope is measured to evaluate the characteristic of the gyroscope. The sensitivity, non-linearity, noise density and the bias stability are measured to 9.7693 mV/deg/s, 04265 %, 2.3 mdeg/s/rtHz and 16.1014 deg/s, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.433-437
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• 2021

As the demand for new and renewable energy increases due to the depletion of fossil fuels, solar power generation, a core energy source for new and renewable energy, requires research on solar modules for high output power generation. In this paper, the electrical characteristics of solar cell strip at the edge and in the center of single-crystal silicon having a semi-square shape were analyzed. The cell strip located in the center showed the efficiency increase by 0.26% compared to the cell strip at the edge of the solar cell. A shingled photovoltaic module was manufactured for each cell strip. As a result, the output power of the module using the cell strip located in the center was higher by 0.992%.

• Korean Journal of Metals and Materials
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• v.48 no.2
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• pp.175-179
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• 2010

We investigated the thermal conductivity of individual single-crystalline PbTe nanowires grown by chemical vapor transport method. Suspended MEMS was utilized to precisely measure the thermal conductivity of an individual nanowire. The thermal conductivity of a PbTe nanowire with diameter of 292 nm was measured to be $1.8W/m{\cdot}K$ at 300 K, which is about two thirds of that of bulk PbTe. This result indicates that the thermal conduction through a PbTe nanowire is effectively suppressed by the enhanced phonon boundary scattering. As the diameter of a PbTe nanowire decreases, the corresponding thermal conductivity linearly decreases.

• Progress in Superconductivity and Cryogenics
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• v.8 no.3
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• pp.13-17
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• 2006

The effect of the addition of the nano size $Y_2O_3$ powder on the microstructurte and superconducting properties of YBCO thin film deposited on LAO single crystalline substrate by TFA-MOD method was studied. Nano size $Y_2O_3$ powder was added to the stoichiometric precursor solution with a cation ratio of Y : Ba . Cu = 1 : 2 : 3 prepared using TFA as chelating agent. Precursor solutions with and without $Y_2O_3$ addition were coated on $LaAlO_3(100)$ single crystalline substrates by dip coating method. Calcination and conversion heat treatments were performed in controlled atmosphere containing moisture Current carrying capacity(Jc) of YBCO film was enhanced about 50% by $Y_2O_3$ doping and it is thought to be due to the better connectivity of YBCO grains and/or the flux pinning by the $Y_2O_3$ particles embedded in YBCO grains.

• Analytical Science and Technology
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• v.37 no.4
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• pp.201-210
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• 2024

Surface-enhanced Raman scattering (SERS) has emerged as a powerful technique for detecting and analyzing chemical and biological molecules at ultra-low concentrations. The effectiveness of SERS largely depends on structures with sub-10 nm gaps, prompting the proposal of various nanostructures as efficient SERS-active platforms. Among these, single-crystalline gold nanowires (AuNWs) are particularly promising due to their large dielectric constants, well-defined geometries, atomically smooth surfaces, and surface plasmon resonance across the visible spectrum, which produce strong SERS enhancements. This review comprehensively explores the synthesis, functionalization, and application of Au NWs in SERS. We discuss various methods for synthesizing AuNWs, including the vapor transport method, which influences their morphological and optical properties. We also review practical applications in chemical and biosensing, showcasing the adaptability of Au NWs-based SERS platforms in detecting a range of analytes, from environmental pollutants to biological markers. The review concludes with a discussion on future perspectives that aim to enhance sensor performance and broaden application domains, highlighting the potential of these sensors to revolutionize diagnostics and environmental monitoring. This review underscores the transformative impact of AuNW-based SERS sensors in analytical chemistry, environmental science, and biomedical diagnostics, paving the way for next-generation sensing technologies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.85-88
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• 2004

Mono-crystalline silicon(mono-Si) is both abundant in our environment and an excellent material for Si device applications. However, single crystalline silicon solar cell has been considered to be expensive for terrestrial applications. For that reason, the last few years have seen very rapid progress in the research and development activities of layer transfer(LT) processes. Thin film Si layers which can be detached from a reusable mono-Si wafers served as a substrate for epitaxial growth. The epitaxial films have a very high efficiency potential. LT technology is a promising approach to reduce fabrication cost with high efficiency at large scale since expensive Si substrate can be recycled. Low quality Si can be used as a substrate. Therefore, we propose one of the major technologies on fabricating thin film Si substrate using a LT. In this paper, we study the LT method using the electrochemical etching(ECE) and solid edge.

• Journal of Surface Science and Engineering
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• v.29 no.5
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• pp.525-531
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• 1996

(Ti1-xAlx)N films were deposited on high speed steel and silicon substrates by reactive sputtering in mixed $Ar-N_2$ discharges. Crystalline phases and microhardness of ($Ti_1_xAl_x$)N films were investigated with variation of the film composition and substrate RF bias voltage. With Al content x of about 0.6, crystalline phase of ( $Ti_1_xAl_x$N films was changed from single-phase NaCl structure to two phase mixture of NaCl and wurtzite structures: Microhardness of ($Ti_1_xAl_x$)N films was largely improved by applying RF bias voltage above 50 V during deposition. Hardness of ($Ti_1_xAl_x$)N films reached a maximum value for Al content x of about 0.4, and 1900 kg/$mm^2$ was obtained for 1$\mu m$-thick ($Ti_{0.6}Al_{0.4}$)N films.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.181-184
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• 2004

Thin films of single phase, polycrystalline silicon germanium (Si$_{1-x}$ Ge$_{x}$) were prepared by ion-beam evaporation (IBE) using Si-Ge multi-phase targets. After irradiation of the targets by a pulsed light ion beam with peak energy of 1 MV, 450 and 480 nm thick films were deposited on Si single crystal and quartz glass substrates, respectively. From XRD analysis, the thin films consisted of a single phase Si$_{1-x}$ Ge$_{x}$, whose composition is close to those of the targets.rgets.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.85-86
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• 2006

Single crystal $AgGaSe_2$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_2$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $AgGaSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=19501 eV-(879{\times}10^{-4} eV/K)T^2/(T+250 K)$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.96-97
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• 2008

Single crystal $AgGaSe_2$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at 420 $^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_2$ source at 630 $^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_2$ thin films measured with Hall effect by van def Pauw method are $9.24\times10^{16}cm^{-3}$ and 295 $cm^2/V{\cdot}s$ at 293 K, respectively.