• 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).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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• pp.92-96
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• 2002

Hot wall epitaxy 방법을 이용하여 chalcopyrite 구조를 가진 고품질의 $AgInS_{2}$ 박막을 성장 하였다. 광전류 스펙트럼을 측정한 결과， 30K에서 300K까지는 단지 A 와 B 두개의 봉우리가 관측되었고 반면에 10K에서는 A,B,C 세 개의 봉우리가 관측되었다. 이때 이들 봉우리들은 band-to-band 전이에 기인하는 것으로 관측되었다. 광전류 측정으로부터 $AgInS_{2}$의 가전자대 갈라짐이 측정되었고 이로부터 10k에서 결정장에 의한 갈라짐 $D_{cr}$과 스핀궤도에 의한 갈라짐 $D_{so}$은 각각 0.150eV와 0.009eV로 관측되었다. 또한 에너지 밴드갭의 온도 의존성 $E_{g}(T)$에 대하여 연구하였고 성장된 $AgInS_{2}$ 박막의 에너지 밴드갭은 1.868eV 임을 알았다.

• 한국재료학회지
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• 제12권7호
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• pp.587-590
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• 2002

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.d.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.157-157
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• 2003

수평 전기로에서 CdIn2Te4 다결정을 용융법으로 합성하고 Bridgman법으로 tetragonal structure의 c축에 평행한 CdIn2Te4 단결정을 성장시켰다. c축에 평행한 시료의 광흡수와 광전류 spectra를 293K에서 10K까지 측정하였다. 광흡수 spectra에 의해 band gap Eg(T)는 varshni공식에 따라 계산한 결과 1.4753eV-(7.78$\times$$10^{-3}$eV/K)T$^2$/(T+2155K)임을 확인하였다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 9.01$\times$$10^{16}$ /㎤, 219 $\textrm{cm}^2$/V.S였다. 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting $\Delta$cr값이 0.2704 eV이며 spin-orbit $\Delta$so 값은 0,1465 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n=1일때 Al-, Bl-와 Cl-exciton 봉우리임을 알았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.79-80
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• 2006

A stoichiometric mixture of evaporating materials for $CdIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CdIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-Insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The temperature dependence of the energy band gap of the $CdIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation. $E_g(T)=2.7116 eV-(7.74{\times}10^{-4} eV)T^2/(T+434)$. The crystal field and the spin-orbit splitting energies for the valence band of the $CdIn_2S_4$ have been estimated to be 0.1291 eV and 0.0248 eV, 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 $AgInS_2$/GaAs epilayer. The three photocurrent peaks observed at 10K are ascribed to the $A_1-$, $B_1-$, and C1-exciton peaks for n = 1.

• 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.

• 한국재료학회지
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• 제11권5호
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• pp.419-426
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• 2001

AgGaSe$_2$ 단결정 박막은 수평 전기로에서 합성한 $AgGaSe_2$ 다결정을 증발원으로 하여, hot wall epitaxy (HWE) 방법으로 증발원과 기판 (반절연성-GaAs(100)) 의 온도를 각각 $630^{\circ}C$, $420^{\circ}C$로 고정하여 박막 결정 성장을 하였다. 10K에서 측정한 광발광 excition 스펙트럼과 이중결정 X-선 요동곡선 (DCRC) 의 반치폭 (FWHM )을 분석하여 단결정 박막의 최적 성장 조건을 얻었다. Hall효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293k에서 각각 4.89$\times$$10^{ 16}$/㎤, 129$\textrm{cm}^2$/V.s였다. 광전류 봉우리의 10K에서 단파장대의 가전자대 갈라짐 (splitting)에 의해서 측정된 $\Delta$C$_{r}$ (crystal field splitting)은 0.1762eV, $$\Delta$S_{o}$ (spin orbit splitting)는 0.2494eV였다 10K의 광발광 측정으로부터 고풍질의 결정에서 볼 수 있는 free excitors과 매우 강한 세기의 중성 주개 bound excitors등의 피크가 관찰되었다. 이때 중성 주개 bound ekciton의 반치폭과 결합에너지는 각각 BmeV와 14.1meV였다. 또한 Haynes rule에 의해 구한 불순물의 활성화 에너지는 141meV였다.rule에 의해 구한 불순물의 활성화 에너지는 141meV였다.

• 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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• 제9권2호
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• pp.96-106
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• 1998

수평 전기로에서 AgInS2 다결정을 합성하여 HWE 방법으로 AgInS2 단결정 박막을 반절연성 GaAs(100) 위에 성장하였다. AgInS2 단결정 박막은 증발원과 기판의 온도를 각각 680℃, 410℃로 성장하였다. 이때 단결정 박막의 결정성이 10 K에서 측정한 광발광 스펙트럼은 597.8 nm(2.0741 eV) 근처에서 엑시톤 방출 스펙트럼이 가장 강하게 나타났으며, 또한 이중결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)도 121 arcsec로 가장 작게 측정되어 최적 성장 조건임을 알 수 있었다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293 K에서 각각 9.35×1023개/㎥, 2.94×10-2㎡/V·s였다. AgInS2 단결정 박막의 광전류 단파장대 봉우리들로부터 10 K에서 측정된 ΔCr(crystal field splitting)은 0.15eV, ΔSo(spin orbit coupling)는 0.0089 eV였다. 광전도 셀로서 응용성을 알아보기 위해 감도(γ), pc/dc(photocurrent/darkcurrent), 최대허용소비전력(maximum allowable power dissipation: MAPD), 응답시간(response time)등을 측정한 결과, S 증기 분위기에 열처리한 광전도 셀의 경우 γ=0.98, pc/dc=1.02×106, MAPD=312 mW, 오름시간(rise time)=10.4 ms, 내림시간(decay time)=10.8 ms로 가장 좋은 특성을 얻었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.156-159
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• 2003

The stochiometric mixture of evaporating materials for the $CuInTe_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CuInTe_2$ mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were $610^{\circ}C\;and\;450^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about $0.5{\mu}m/h$. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). From the photocurrent spectra, we have found that values of spin orbit coupling ${\Delta}So$ and crystal field splitting ${\Delta}Cr$ ware $0.283{\underline{3}}eV\;and\;0.120{\underline{0}}eV$, respectively.