• 한국결정성장학회지
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• 제10권4호
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• pp.286-291
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• 2000

수직 Bridgman법으로 $Cd_{1-x}Mn_{x}Te$ 단결정을 성장시켜 자기장과 파장을 변화시키면서 Faraday회전을 측정하였다. Verdet 상수값은 포톤의 에너지가 높은 쪽으로 이동함에 따라 흡수단 근처에서 최대였고, 조성비 x에 따라 증가하다가 x=0.40 이상에서 감소하였다. $Cd_{1-x}Mn_{x}Te$ 단결정을 Faraday 소자로 이용할 경우, 흡수단 근처에서 Faraday 회전이 가장 크게 일어나는 $Cd_{0.60}Mn_{0.38Te}$ 단결정이 적합하고,광원으로 He-Ne레이저를 사용할 경우에는 $Cd_{0.62}Mn_{0.40}Te$ 단결정이 유용함을 알 수 있었다.

• 한국결정성장학회지
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• 제5권4호
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• pp.306-317
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• 1995

수평 브릿지만법은 갈륨 비소 반도체 결정을 성장시키는데 많이 사용된다. 수평 브릿지만 법에 의하여 성장된 단결정 내에서 불순물 분포를 알아보기 위하여 성장 과정 중의 액상에서 열전달, 물질전달, 유체흐름과 고상에서 열전달을 의사 정상상태를 가정하여 2차원 및 3차원 모델을 세우고 유한요소법에 의하여 수치모사하였다. 이때 고-액 계면의 위치와 형태도해의 일부분으로 다른 해들과 동시에 구하였다. 2차원 단열 경계조건에서는 3차원의 계면이 2차원의 경우보다 덜 휘어졌고, 대류 강도는 비슷하였다. 대류강도의 증가에 따라 수직 편석은 최대값을 보였으나 계면이 2차원에서 더 휘어져 최대값은 2차원에서 대류 강도가 더 작을 때 나타났다.

• 한국주조공학회지
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• 제10권4호
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• pp.324-331
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• 1990

The single crystal of CdTe was grown by modified 6 zone Bridgman method under the conditions of excess Te and excess Cd. To prevent the constitutional supercooling, the crystal growth was done under the temperature gradient of $17^{\circ}C/cm$ in front of the solid /liquid interface and the growth rate was 3mm/hr. The grain morphologies and the growth mechanism were investigated in excess Te and excess Cd conditions. The grain size of excess Te crystal was increased with an increase of the distance from the tip but, in the case of excess Cd crystal, single crystal was not obtained because of the cavities due to the excess Cd vapors so that the grain size was not increased with an increase of the distance from the tip. In addition, the growth of single crystal of CdTe was done with repeated necking ampoule. It was found that the necking had no effects on the grain selection because the cavities trapped in the necking portion acted as heterogeneous nucleation sites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.347-351
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• 2003

A p-$CdIn_2Te_4$ single crystal has been grown by the Bridgman method without a seed crystal in a tree-stage vertical electric furnace. From photocurrent measurements, it was found that three peaks, A, B, and C, corresponded to an intrinsic transition due to the band-to-band transition from the valence band states ${\Gamma}_7(A),\;{\Gamma}_6(B),\;and\;{\Gamma}_7(C)$ to the conduction band state ${\Gamma}_6$, respectively. Also, the valence band splitting of the $CdIn_2Te_4$ crystal has been confirmed by photocurrent spectroscopy. The crystal field splitting and the spin orbit splitting were obtained to be 0.2360 and 0.1119 eV, respectively. Also, the temperature dependence of the band gap energy of the $CdIn_2Te_4$ crystal has been driven as the following equation of $E_g(T)\;=E_g(0)\;-\;(9.43\;{\times}\;10^{-3})T^2/(2676\;+\;T)$. In this equation, the Eg(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band state A, B, and C, respectively. The band gap energy of the p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.112-113
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• 2006

A stoichiometric mixture for $Cdln_2Te_4$ single crystal was prepared from horizontal electric furnace. The $Cdln_2Te_4$ single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The quality of the grown crystal has been investigated by the x-ray diffraction and the photoluminescence measurements. The (001) growth plane of oriented $Cdln_2Te_4$ single crystal was confirmed from back-reflection Laue patterns. The carrier density and mobility of $Cdln_2Te_4$ single crystal measured with Hall effect by van der Pauw method are $8.61{\times}10^{16}\;cm^{-3}$ and $242\;cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $Cdln_2Te_4$ single crystal obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;1.4750\;eV\;-\;(7.69{\times}\;10^{-3}\;eV)T^2/(T+2147)$.

• 한국결정성장학회지
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• 제8권4호
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• pp.550-554
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• 1998

Bridgman-Stockbarger법에서 thermal screen의 역할을 하는 새로운 방법을 6inch 형석(CaF2) 단결정성장을 위하여 고안하였다. 본 방법으로 poly-grain으로의 성장과 내부 cavity, 그리고 solid-liquid(SL) interface를 제어할 수 있었다. Graphite pipe와 ceramic warmer를 사용하여 성장한 6inch의 CaF2 결정은 완전한 단결정으로 성장하였다. 이때의 조건은 2mm/hr의 성장속도, 성장구역에서의 $14^{\circ}C$/cm의 온도구배, 그리고 도가니의 conical tip에서 $1324^{\circ}C$의 온도를 나타내었다. 내부 cavity에 의해 발생되는 light scattering 현상은 성장속도를 감소시키거나 융액을 회전함으로써 제어할 수 있었다.

• 한국자기학회지
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• 제19권5호
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• pp.186-190
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• 2009

본 연구에서는 수직 Bridgman 법으로 묽은 자성 반도체 Cd$_{1-x}$Mn$_x$Te 단결정을 성장시켜 Mn의 조성비 변화에 따른 자기광학적 특성과 응용성을 조사하였다. X-선 회절 실험으로부터 x < 0.82 조성에 대하여 zinc-blende 구조임을 확인하였다. 띠 간격 에너지는 온도 감소와 Mn 조성비 증가에 대하여 선형적으로 증가하였다. Faraday 회전은 광 에너지 증가 때문에 띠 간격 에너지 근처에서 증가하였고, Mn 조성비 x가 증가함에 따라 증가하였다. Cd$_{0.62}$Mn$_{0.38}$Te 결정을 이용한 광 아이솔레이트의 아이솔레이션과 삽입손실은 45와 0.35 dB이었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.278-281
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• 2003

The p-CIn2Te4 single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The quality of the grown crystal has been investigated by the x-ray diffraction and the photoluminescence measurements. From the photoluminescence spectra of the as-grown CdIn2Te4 crystal and the various heat-treated crystals, the (Do, X) emission was found to be the dominant intensity in the photoluminescence spectrum of the CdIn2Te4:Cd, while the (Ao, X) emission completely disappeared in the CdIn2Te4:Cd. However, the (Ao, X) emission in the photoluminescence spectrum of the CdIn2Te4:Te was the dominant intensity like an as-grown CdIn2Te4 crystal. These results indicated that the (Do, X) is associated with VTe acted as donor and that the (Ao, X) emission is related to VCd acted as acceptor, respectively. The p-CdIn2Te4 crystal was found to be obviously converted into the n-type after annealing in the Cd atmosphere. The origin of (Do, Ao) emission and its TO phonon replicas is related to the interaction between donors such as VTe or Cdint, and accepters such as VCd or Teint. Also, the In in the CdIn2Te4 was confirmed not to form the native defects because it existed in the stable form of bonds.

• 한국결정성장학회지
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• 제9권2호
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• pp.180-184
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• 1999

수집 Bridgman 법을 이용하여 $Mg_{0.15}Zn_{0.85}Te$ 와 $Mg_{0.15}Zn_{0.85}Te:Co^{2+}$(0.001%) 단결정을 성장시켰다. 성장된 시료들에 대하여 광흡수 특성을 연구하였다. 광흡수결과 $Mg_{0.15}Zn_{0.85}Te$단결정에서는 exciton과 관련된 흡수 peak들이 나타났으며, 이 peak들은 온도증가와 함께 장파장쪽으로 이동하였고, 100K이상의 온도에서 excitionic band gap의 온도계수 $-5.8{\times}10^{-4}\;eV/K$eV/K 이었다. $Mg_{0.15}Zn_{0.85}Te$ : $Co^{2+}$단결정에서는 $Co^{2+}$이온에 기인된 $A-band:^4A_2(^4F) {\to}^4T_1(^4F),\; B-band:\; ^4A_2(^4F){\to}^4T_1(^4P)$의 intracenter 전이와 흡수단 부근에서 charge transfer에 기인한 photoionization transition에 관련된 C-band를 6--~770nmdnk 파장영역에서 관측하였다. 이들을 결정장 이론과 Lucovsky formular에 의해 결정장 매개변수와 Racah 매개변수, 전하이동 에너지 값을 결정하였다.

• 한국재료학회지
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• 제13권3호
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• pp.195-199
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• 2003

The $p-CdIn_2$$Te_4$single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The quality of the grown crystal has been investigated by the x-ray diffraction and the photoluminescence measurements. From the photoluminescence spectra of the as-grown $CdIn_2$$Te_4$crystal and the various heat-treated crystals, the ($D^{\circ}$, X) emission was found to be the dominant intensity in the photoluminescence spectrum of the $CdIn_2$T $e_4$:Cd, while the ($A^{\circ}$, X) emission completely disappeared in the $CdIn_2$T $e_4$:Cd. However, the ($A^{\circ}$, X) emission in the photoluminescence spectrum of the $CdIn_2$T $e_4$:Te was the dominant intensity like an as-grown $CdIn_2$T $e_4$crystal. These results indicated that the ($D^{\circ}$, X) is associated with $V_{Te}$ acted as donor and that the ($A^{\circ}$, X) emission is related to $V_{cd}$ acted as acceptor, respectively. The $p-CdIn_2$T $e_4$crystal was found to be obviously converted into the n-type after annealing in the Cd atmosphere. The origin of ( $D^{\circ}$, $A^{\circ}$) emission and its TO phonon replicas is related to the interaction between donors such as $V_{Te}$ or $Cd_{int}$, and accepters such as $V_{cd}$ or T $e_{int}$. Also, the In in the $CdIn_2$X$CdIn_4$was confirmed not to form the native defects because it existed in the stable form of bonds.