• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.122-123
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• 2007

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 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)=1.9501 eV - $(8.79{\times}10^{-4}\;eV/K)T^2$/(T+250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_2$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $AgGaSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-},\;B_{1^-},\;and\;C_{1^-}$exciton peaks for n=1.

• 센서학회지
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• 제13권2호
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• pp.157-167
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• 2004

A stoichiometric mixture of evaporating materials for $CuAlSe_{2}$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CuAlSe_{2}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $680^{\circ}C$ and $410^{\circ}C$, respectively. 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 $CuAlSe_{2}$ single crystal thin films measured with Hall effect by van der Pauw method are $9.24{\times}10^{16}cm^{-3}$ and $295cm^{2}/V{\codt}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$ = 2.8382 eV - ($8.68{\circ}10^{-4}$ eV/K)$T^{2}$/(T + 155 K). The crystal field and the spin-orbit splitting energies for the valence band of the $CuAlSe_{2}$ have been estimated to be 0.2026 eV and 0.2165 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $CuAlSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1-}$, $B_{1-}$, and $C_{1-}$ exciton peaks for n = 1.

• 센서학회지
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• 제16권1호
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• pp.1-6
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• 2007

A silver indium sulfide ($AgInS_{2}$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_{2}$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_{2}$ was investigated by means of the photocurrent measurement. The crystal field splitting, ${\Delta}cr$, and the spin orbit splitting, ${\Delta}so$, have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_{g}$(T), was determined.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.237-242
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• 2001

The stochiometric mix of evaporating materials for the CuGaSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuGaSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 610$^{\circ}C$ and 450$^{\circ}C$, respectively The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuGaSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting Δ So and the crystal field splitting ΔCr were 91 meV and 249.8 meV at 20 K, respectively. From the Photoluminescence measurement on CuGaSe$_2$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy 7f neutral acceptor bound excision were 8 meV and 35.2 meV, respectivity. By Haynes rule, an activation energy of impurity was 355.2 meV

• 한국결정성장학회지
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• 제25권5호
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• pp.173-181
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• 2015

A stoichiometric mixture of evaporating materials for $BaIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2S_4$ single crystal thin films measured from Hall effect by van der Pauw method are $6.13{\times}10^{17}cm^{-3}$ and $222cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.0581eV-(3.9511{\times}10^{-3}eV/K)T^2/(T+536K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2S_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2S_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{24}$-exciton peaks for n = 24.

• 한국결정학회지
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• 제12권4호
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• pp.197-206
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• 2001

수평 전기로에서 AgInS₂ 다결정을 합성하여 HWE(Hot Wall Epitaxy)방법으로 AgInS₂ 단결정 박막을 반절연성 GaAs(100)기판에 성장시켰다. AgInS₂ 단결정 박막의 성장 조건은 증발원의 온도 680℃, 기판의 온도 410℃였고 성장 속도는 0.5㎛/hr였다. AgInS₂ 단결정 박막의 결정성의 조사에서 10 K에서 광발광(photoluminescence)스펙트럼이 597.8 nm(2.0741 eV)에서 exciton emission스펙트럼이 가장 강하게 나타났으며, 또한 이중결정 X-선 요동곡선(DCRC)의 박폭치(FWHM)도 121 arcsec로 가장 작아 최적 성장 조건임을 알수 있었다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 9.35×10/sup 16/㎤, 294㎠/V·s 였다. AgInS₂ /SI(SEmi-Insulated) GaAs(100) 단결정 박막의 광흡수와 광전류 spectra를 293K에서 10K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap E/sub g/(T)는 Varshni 공식에 따라 계산한 결과 2.1365eV-(9.89×10/sup-3/eV/K/)T²(T+2930K)이었으며 광전류 스펙트럼으로부터 Hamiltopn matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting Δcr값이 0.1541eV이며 spin-orbit Δso 값은 0.0129eV임을 확인하였다. 10K일때 광전류 봉우리들은 n=1 일때 A₁-, B-₁와 C₁-exction 봉우림을 알았다.

• 한국결정학회지
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• 제11권3호
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• pp.137-146
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• 2000

The stoichiometric mix of evaporating materials for he CuInS₂ single crystal thin films was prepared. To obtain the single crystal thin films, CuINS₂ mixed crystal was deposited on etched semi-insulator GaAs(100) substrate by the hot wall epitaxy(HWE) system. The source and substrate temperature were 640℃ and 430℃, respectively and the thickness of the single crystal thin films was 2 ㎛. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility deduced from Hall data are 9.64x10/sup 22//㎥ and 2.95x10/sup -2/ ㎡/V·s, respectively at 293 K. he optical energy gap was found to be 1.53 eV at room temperature. From the photocurrent spectrum obtained by illuminating perpendicular light on the c-axis of the thin film, we have found that the values of spin orbit coupling splitting ΔSo and the crystal field splitting ΔCr were 0.0211 eV and 0.0045 eV at 10K, respectively. From PL peaks measured at 10K, were can assign the 807.7 nm (1.5350 eV) peak to E/sub x/ peak of the free exciton emission, the 810.3 nm(1.5301 eV) peak to I₂ peak of donar-bound exciton emission and the 815.6 nm(1.5201 eV) peak to I₁ peak of acceptor-bound excition emission. In addition, the peak observed at 862.0 nm(1.4383 eV) was analyzed to be PL peak due to donor-acceptor pair(DAP).

• 한국결정성장학회지
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• 제23권6호
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• pp.283-290
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• 2013

수평 전기로에서 $MgGa_2Se_4$ 다결정을 합성하여 HWE(Hot Wall Epitaxy)방법으로 $MgGa_2Se_4$ 단결정 박막을 반절연성 GaAs(100)기판에 성장시켰다. $MgGa_2Se_4$단결정 박막의 성장 조건은 증발원의 온도 $610^{\circ}C$, 기판의 온도 $400^{\circ}C$였고 성장 속도는 $0.5{\mu}m/hr$였다. 이때 이중결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)도 212 arcsec로 가장 작아 최적 성장 조건임을 알 수 있었다. $MgGa_2Se_4$/SI(Semi-Insulated) GaAs(100) 단결정 박막의 광흡수와 광전류 spectra를 293 K에서 10 K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap Eg(T)는 varshni공식에 따라 계산한 결과 $E_g(T)=2.34 eV-(8.81{\times}10^{-4}eV/K)T^2/(T+251K)$이었으며 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting energy ${\Delta}cr$값이 190.6 meV이며 spin-orbit energy ${\Delta}so$값은 118.8 meV임을 확인하였다. 10 K일 때 광전류 봉우리들은 n = 1, 27일때 $A_{1^-}$, $B_{1^-}$와 $C_{27}-exciton$ 봉우리임을 알았다.

• 폴리머
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• 제26권6호
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• pp.752-758
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• 2002

사슬길이가 서로 다른 두 종류의 n-paraffin 혼합물이 결정을 형성할 때 사슬의 움직임과 형성된 라멜라의 구조를 조사하기 위하여 FTIR, FT-Raman, XRD 실험방법을 이용하였다. FTIR crystal field splitting, Raman longitudinal acoustic mode, 그리고 SAXS long period 측정 결과들을 비교하여 사슬길이가 다른 두 n-paraffin 사슬이 혼합되어 하나의 라멜라를 형성하거나 분리되어 각각의 라멜라를 형성하는 과정을 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.179-180
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• 2007

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 der Pauw method are $4.05{\times}\;10^{16}/cm^3$, $139\;cm^2/V{\cdot}s$ at 293 K. respectively. 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, $E_g(T)=1.9501\;eV\;-\;(8.79{\times}10^{-4}\;eV/K)T^2$/(T + 250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_2$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the phcitocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the $\Gamma_5$ states of the valence band of the $AgGaSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-, and $C_1$-exciton peaks for n = 1.