• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1260_1261
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• 2009

A detailed investigation and structure of tested samples are clearly presented. As a reference, $Ge_1Se_1Te_2$/Sb only sample was also investigated. We used compound of Ge-Se-Te material for phase-change cell. Actually, the performance properties have been improved surprisingly then conventional Ge-Sb-Te. However, crystallization time was as long as ever for amorphization time. We conducted this esperiment in order to solve that problem by doping-Sb.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.10a
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• pp.82-85
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• 1988

In the present study, we have investigated a novel photothermal imaging technique in $80^{\circ}$ deposited Ge Se film which do not utilize silver and deposited a-$Ge_{25}Se_{75}$ films was measured with the exposure time and annealing time. The results showed that the maximum changing rate of thickness was 3% in exposured film and 14% in postexposure annealing film.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.2
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• pp.140-148
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• 1993

In this study, the electrical and optical properties of amorphous, crystallization and thin film of As-Ge-Se Chalcogenide System was investigated. Typical composition of this material has $As_{20~50}Se_{40~70} and Ge_{10~40}$ at%. Materials having Se was fixed to 40 at% and As was above 30 at% much more increased the electrical conductivity. After crystallization at the temperature of $476^{\circ}C$ for 3 hour was showed the best electrical conductivity of 1.74E-13$(\Omega cm)^{-l}$. And the main crystalline phase of this sample can be investigated using the mixed crystalline, i.e, $GeSe_2 and As_2Se_3$ phases. The thin film shows the optical absorption coefficient in the range $2{times}10^3 to 7{times}10^4$ and the optical energy gap of 1.85eV.

• Journal of the Korean Ceramic Society
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• v.52 no.2
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• pp.108-113
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• 2015

In an effort to evaluate the practicability of an imprinting technique for amorphous chalcogenide film in Ge-based compositions, we investigate the deformation behavior of the surface of amorphous $GeSe_2$ film deposited via a thermal evaporation route according to varying static loads applied at elevated temperatures. We observe that, under these static loading conditions, crystallization tends to occur on its surface relatively more easily than in As-based $As_2Se_3$ films. As for the present $GeSe_2$ film, higher processing temperatures are required in order to make its surface reflect the given stamp patterns well; however, in this case, its surface becomes partially crystallized in the monoclinic $GeSe_2$ phase. The increased vulnerability of this amorphous $GeSe_2$ film toward surface crystallization under static loading, when compared with the $As_2Se_3$ counterpart, is explained in terms of the topological aspects of its amorphous structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.110-111
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• 2006

In this paper, we investigated resistance characteristic of chalcogenide material for next generation ReRAM nonvolatile memory device with laser irradiation. A AES is used to test Ag doping ratio into a As-Ge-Se-S thin film. A sample resistance was observed in real time with He-Ne laser(632.8nm). As a result, resistance of thermal treated As-Ge-Se-S thin film was $500{\Omega}$ which is smaller than initial $1.3M{\Omega}$. A resistance of non-treated Ag/As-Ge-Se-S thin film was $200{\Omega}$ which is lower than $35M{\Omega}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.83-84
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• 2006

For phase transition method, good recording sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, A retention time is very important part for phase transition. In our presentation wall, we chose Ge-Se-Te material to use a Se material which has good optical sensitivity than Sb. A Ge-Se-Te sample was fabricated and Irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light.

• Korean Journal of Materials Research
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• v.26 no.11
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• pp.598-603
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• 2016

The recent development of electro-optic devices and anticorrosion media has led to the necessity to investigate infrared optical systems with solid-solid interfaces of materials that often have the characteristic of amorphousness. One of the most promising classes of materials for those purposes seems to be the chalcogenide glasses. Chalcogenide glasses, based on the Ge-Sb-Se system, have drawn a great deal of attention because of their use in preparing optical lenses and transparent fibers in the range of 3~12 um. In this study, amorphous Ge-Sb-Se chalcogenide for application in an infrared optical product design and manufacture was prepared by a standard melt-quenching technique. The results of the structural, optical and surface roughness analysis of high purity Ge-Sb-Se chalcogenide glasses are reported after various annealing processes.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.288.1-288.1
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• 2014

We investigated the optical properties of Ge1-xSex and Ge1-x-ySexAsy amorphous semiconductor films using spectroscopic ellipsometry and Raman spectroscopy. The dielectric functions and absorption coefficients of the amorphous films were determined from the measured ellipsometric angles. We obtained the optical gap energies and Urbach energies from the absorption coefficients, and found a strong bowing effect in the optical gap energy of Ge1-x-ySexAsy where the endpoint binaries were Ge0.50Se0.50 and Ge0.31As0.69. Based on the correlation between optical gap energies and Urbach energies, the large bowing parameter was attributed to the electronic disorder. We found the composition dependence of several phonon modes using Raman spectroscopy. For Ge1-x-ySexAsy, the D mode (232-267 cm-1) changed from As-As (or As3 pyramid), to As(Se1/2)3 pyramid, and finally to Se clusters, as the Se composition increased. Resonant Raman phenomenon was observed in Ge0.38Se0.62 at a laser excitation of 514 nm (2.41 eV). We verified that this laser energy corresponds to the transition energy of Ge0.38Se0.62 using the second derivative of the dielectric function of Ge0.38Se0.62.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.77-81
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• 1992

The purpose of this research was th evaluate conductivity of electricity of Ge-Se-Bi system Chalcogenide glass as a amorphous semiconductor by observing its dissolution and crystallization. In this experiment. Ge-Se-Bi metal powder in the rage of $Ge_{12-25}$, $Se_{65-85}$, $Bi_{2.5-15}$ was used as the sample ore. The ore was. put into a vaccous quartz tube and then melted. The condition of heat treatment was to dispose it to $1000^{\circ}C$ heat for 10 hours and then rapidly quenched it at $3834^{\circ}C$/see. The crystallization of the fused sample ripened as the change of temperature and time, after the crystal core was formell. At that time it was possible to observe the state that $Bi_2Se_3$ and $GeSe_2$ were crystallized. In the experiment of making memberance, the memberance was produced by using the previously experimented bulk sample. And decrystalization was well progressed when Ge was over 15 at %, Se was over 70 at %, and Bi was under 10 at%. As for bulk. when Ge was fixed to 20 at %, the conducting of electricity was increased as Bi gained at %. In the case of memberance, the conductivity was much more increased than that of bulk sample as the increase of at the increase of at % of Bi. In the experiment on $Ge_{20}$, $Se_{77.5}$ and $Bi_{2.5}$, the crystallization sswas most vigorous when they were kept at $330^{\circ}C$ for 4 hours.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.11
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• pp.106-112
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• 1992

In this paper, we analyze the structure characteristics of $As_{40}Se_{50-x}S_{x}Ge_{10}$ system bulk and thin films. As the results of XRD patterns, it identified amorphous state. In order to find the glass transition temperature($T_g$), crystallization($T_c$) and melting point ($T_m$)of bulk sample, it ascertained that TS1gT is 238$^{\circ}C$ in $As_{40}Se_{15}S_{35}Ge_{10}$, and 231$^{\circ}C$ in $As_{40}Se_{25}S_{25}Ge_{10}$ & $As_{40}Se_{50}Ge_{10}$ following the thernal analysis by DSC, DTA, & TGA method. Also it was confirmed the phase seperation of continuous phase and dispertion phase by the optical texture of polarizing microscope and $T_g$ near 20$0^{\circ}C$ in thin film. Therefore, it was found that it occurs the phase seperation of Ge-rich dontinuous phase and Se-rich dispersion phase following the EDS analysis of thin film and the surface SEM photograph.