• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.306-317
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• 1995

Abstract Gallium arsenide crystal is usually grown from the melt by the horizontal Bridgman method. We constructed pseudo - steady - state model for crystal growth of GaAs which inclue melt, crystal and the free interface. Mathematical equations of the model were solved for flow, temperature, and concentration field in the melt and temperature field in the crystal. The location and shape of the interface were also solved simultaneously. In 2 - dimensional model, the shape of the interface is flat with adiabatic thermal boundary condition, but it becomes curved with completely conducting thermal boundary condition. In 3 - dimensional model, the interface is less curved than 2 - dimensional case and the flow intensity is similar to that of 2 - dimensional case. With the increase of flow intensity vertical segregation shows maximum value in both 2 - and 3 - D model. However, the maximum value occurs in lower flow intensity in 2 - D model because the interface is more curved for the same flow intensity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.185-188
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• 1996

The doped n-type $Al_{x}Ga_{1-x}Sb$ crystals were grown by the vertical Bridgman method at composition ratio x=0, x=0.1, x=02 respectively. The lattice constants of the $Al_{x}Ga_{1-x}Sb$ crystals were 6.096${\AA}$, 6.097${\AA}$, 6.106${\AA}$ at composition ratio respectively. The carrier concentration, the resistivity, and the carrier mobility measured by the Van der Pauw method at x-0 were n≡1 x $10^{17}$$cm^{-3}$, $\rho$≡0.15 ${\Omega}$-cm, ${\mu}$$_{n}$≡500 $\textrm{cm}^2$$V^{-1}$$sec^{-1}$ at 300K. The carrier concentration, the resistivity, and the carrier mobility measured by the Van der Pauw method at x=0.1 were n≡2.96 x $10^{15}$$cm^{-3}$, $\rho$≡103 $\textrm{cm}^2$$V^{-1}$$sec^{-1}$ at 300K.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.180-184
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• 1999

The single crystals of $Mg_{0.15}Zn_{0.85}Te$ and $Mg_{0.15}Zn_{0.85}Te:Co^{2+}$(0.001%) were grown by vertical Bridgman method. Optical absorption properties of this compound were studied. As a result of the optical absorption spectra of $Mg_{0.15}Zn_{0.85}Te$, absorption peaks were related to exciton and the exciton level redshifts with increasing temperature, and temperature coefficient given to the value of $-5.8{\times}10^{-4}\;eV/K$ for the temperature range above 100 K. in the $Mg_{0.15}Zn_{0.85}Te:Co^{2+}$(0.001%) single crystal, the intracenter transitions due to $Co^{2+}$ ions were detected for $A-band:^4A_2(^4F) {\to}^4T_1(^4F),\; B-band:\; ^4A_2(^4F){\to}^4T_1(^4P)$, and the charge transfer transition near the absorption edge was observed in the wavelength range of 500 to 800 nm. According to the crystal field theory and Lucovsky formula, the crystal field parameter, Racah parameter and charge transfer energy were determined.

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.236-245
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• 1993

Single crystals, SbSI : V, SbSeI : V, BiSI : V, BiSeI : V, SbSI : Cr, SbSeI : Cr, BiSI : Cr, BiSeI : Cr, SbSI : Ni, SbSeI : Ni, BiSI : Ni, and BiSeI : Ni were grown by the vertical Bridgman method. It is found that the grown single crystals have an orthorhombic structure and the indirect optical transitions. The temperature dependence of energy gap shows the two reflection point related with the phase transitions and is well fitted with Varshni equation in the continuous region. The optical absorption peaks due to the doped impurities (V, Cr and Ni) are respectively attributed to the electron transitions between the split energy levels of $V^{+2}$, $Cr^{+2}$ and $Ni^{+2}$ ions sited at $T_d$ symmetry of the host lattice.

• Korean Journal of Crystallography
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• v.7 no.1
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• pp.44-56
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• 1996

CuInTe2 synthesised in a horizontal electric furnace was found to be polycrystalline. Single crystals of CuInTe2 were grown with the vertical Bridgman technique. The structure, Hall effect of the crystals were measured in the temperature range 30 to 293K. Both the polycrystals and single crystals of CuInTe2 were tetragonal in structure. The lattice constants of the polycrytals were measured as a=6.168Å and c=12.499Å, with c/a=2.026, these of the single crystals were measured as a=6.186Å and c=12.453Å, with c/a=2.013. The growth plane of the oriented single crystals was confirmed to be a (112) plane from the back-reflection Laue patterns. The Hall effect of the CuInTe2 single crystals was measured with the method of van der Pauw The Hall data of the samples measured at room temperature showed a carrier concentration of 2.14×1023holes/m3, a conductivity of 739.58Ω-1m-1, and a mobility of 2.16×10 -2m 2/V·s for the sample perpendicular to the c-axis. Values of 1.51×1023holes/m3, 717.55Ω-1m-1, and 2.97×10-2 m2/V·s were obtained for the sample parallel to the c-axis. The Hall coefficients for the samples both perpendicular and parallel to the c-axis in the temperature range 30K to 293K were always positive values. Thus the CuInTe2 single crystal was determined to be a p-type semiconductor.

• Korean Journal of Materials Research
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• v.13 no.3
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.62-65
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• 1995

CdTe crystals were grown by the vertical Bridgman method. P-type DcTe crystals were grown with Cd:Te= 1:1.001 wt. % ratio, while n-type CdTe crystals were 1:1 Also, CdTe:In crystals were investigated, Lattic constants were 6.489${\AA}$ for p-type 6.480${\AA}$for n=type and 6.483${\AA}$ for CdTe:In EPD was 10$\^$-3/-10$\^$4/cm$\^$-2/ for n-, p-type CdTd, 10$\^$4/-10$\^$5/cm$\^$-2 for Cd:Te:In using by E-Ag solution for (111) plane The carrier concentration, the resistivity and the Hall carrier mobility measured by the van der Pauw method were p=5.78${\times}$10$\^$15/cm$\^$-3/, $\rho$=20.2$\Omega$cm, ${\mu}$$\sub$p/=75.6cm$\^$-2/ V$\^$-1/ sec$\^$-1/ for p-typem n=2.98${\times}$10$\^$16/cm$\^$-3/, $\rho$=0.214$\Omega$cm, ${\mu}$$\sub$p/=978.9cm$\^$-2/ V$\^$-1/ sec$\^$-1/ for n-type and n=7.45${\times}$10$\^$16/cm$\^$-3/, $\rho$=1.54 ${\times}$10$\^$3/$\Omega$cm, ${\mu}$$\sub$p/=658.4 cm$\^$-2/ V$\^$-1/ sec$\^$-1/ for CdTe:In crystals, Transmittance of p-type CdTe was 61% that of n-type was 65%, Cd:Te:In showed 60% IR transmittance.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.816-819
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• 1992

Binary compound semiconductor InSb crystal which has direct-transition energy gap (0.17 ev) grown by vertical Bridgman method, then the electric-magnetic and optical properties of InSb crystal were surveyed. The growth rate of the crystals was 1mm/hr and the lattice constant $a_\circ$ of the grown crystal was 6.4863$\AA$. The electrical properties were examined by the Hall effect measurement with the van der Pauw method in the temperature range of 70$\sim$300K, magnetic field range of 500$\sim$10000 gauss. The undoped InSb crystal was n-type, the concentration and the electron mobility were 2$\sim$6 ${\times}$ $10^{16}$$\textrm{cm}^{-3}$ and carrier mobility was 6$\sim$2${\times}$$10^{4}$$cm^{2}$/v.sec at 300K, respectively. The carrier mobility was decreased with $T^{-1/2}$ due to the lattice scattering above 100K, and decreased by impurity scattering below100K. The magnetoresistance was increased 190% at 9000 gauss as compared with non-appliced magnetic field and the magnetoresistance was increased with increasing the magnetic field. Also, the Hall voltage was increased with increasing the magnetic field and decreasing the thickness of sample. The optical energy band gap of InSb at room temperature determined using the IR spectrometer was 0.167eV. The diffusion depth of Zn into InSb proportionally increased with the square root of diffusion time and the activation energy for Zn diffusion was 0.67eV. The temperature dependence of diffusion coefficient was $D=4.25{\times}10^{-3}$exp (-0.67/$K_BT$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.77-80
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• 1995

GaSb crystals were grown by the vertical Bridgman method. P-type GaSb crystals were grown with Ga:Sb=1:1 at % ratio without dopants and with Te, respectively. Also, GaSb:Te crystals were investigated. Lattice constants were 6.117${\AA}$ for p-type. The carrier concentration, the resistivity, and the carrier mobility measured by the van der Pauw method were p≡8 x $10^{16}$$cm^{-3}$, p≡0.20$\Omega$-cm, ${\mu}$$_{n}$≡$400\textrm{cm}^2$$V^{-1}$$sec^{-1}$ for p-type, n≡1 x $10^{17}$$cm^{-3}$, p≡0.15 $\Omega$-cm, ${\mu}$$_{n}$≡$500\textrm{cm}^2$$V^{-1}$$sec^{-1}$ for n-type at 300K. In case of treating with metal ion of $Ru^{+3}$, $Pt^{+1}$, p≡2 x $10^{17}$$cm^{-3}$, p≡0.08$\Omega$-cm, ${\mu}$$_{n}$≡420$\textrm{cm}^2$$V^{-1}$$sec^{-1}$ for p-type, n≡2.5 x $10^{17}$$cm^{-13}$, p≡0.07 $\Omega$-cm, ${\mu}$$_{n}$≡520$\textrm{cm}^2$$V^{-1}$$sec^{-1}$ for n-type were obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.179-182
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• 2004

The $p-CdIn_2Te_4$ 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. From the Photoluminescence spectra of the as-grown $CdIn_2Te_4$ crystal and the various heat-treated crystals, the $(D^{o},X)$ emission was found to be the dominant intensity in the photoluminescence spectrum of the $CdIn_2Te_4:Cd$, while the $(A^{o},X)$ emission completely disappeared in the $CdIn_2Te_4:Cd$. However, the $(A^{o},X)$ emission in the photoluminescence spectrum of the $CdIn_2Te_4:Te$ was the dominant intensity like an as-grown $p-CdIn_2Te_4$ crystal. These results indicated that the $(D^{o},X)$ is associated with $V_{Te}$ acted as donor and that the $(A^{o},X)$ emission is related to $V_{Cd}$ acted as acceptor, respectively. The $p-CdIn_2Te_4$ crystal was found to be obviously converted into the n-type after annealing in the Cd atmosphere. The origin of $(D^{o},\;A^{o})$ 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 $Te_{int}$. Also, the In in the $CdIn_2Te_4$ was confirmed not to form the native defects because it existed in the stable form of bonds.