n-CdS:Co/p-Si Heterojunction 태양전지에 대한 연구

柳相河,李相烈 조선대학교 기초과학연구소 1986 自然科學硏究 Vol.9 No.1

n-CDS:Co/p-Si heterojunction solar cells, fabricated by chemical bath deposition method of CdS:Co on single crystal silicon substrates, are reported. The structural, spectral response and V-I characteristics of n-CdS:Co/p-Si heterojunction solar cell studied. The open-circuit voltage, short-circuit current and fill factor of the n-CdS:Co/p-Si heterojunction solar cell was 0.35V, 29mA/cm^2 and 0.54 under 80mW/cm^2 illumination condition and the conversion efficiency was 5.48%.

n-CdS/P-Si Heterojunction 태양전지 제작 및 전기적 특성에 관한 연구

柳相河,洪光俊 조선대학교 기초과학연구소 1985 自然科學硏究 Vol.8 No.1

CdS thin films were deposited by chemical bath deposition method. The CdS thin films have simple cubic structure with lattice constant 5.818 A and polycrystalline with orientation (111), (220) and (311). n-CdS/p-Si heterojunition solar cells are fabricated, depositing n-CdS thin films on p-Si substrates with orientation (422) by chemical bath depositing method. Under 80mW/㎠ condition the parameters for the typical cell were as followed; open circuit voltage V_oc=0.53V, short circuit current I_sc=11.3mA, fill factor FF=0.35 and conversion efficiency η=2.62%.

고속도로 생애주기비용[LCC] 분석기법의 발전방향

유상하,지동한,권오철,엄인섭 대한토목학회 2004 대한토목학회지 Vol.52 No.8

$CuInTe_2$ 단결정 성장과 특성연구(I)

유상하,홍광준 한국결정학회 1996 韓國結晶學會誌 Vol.7 No.1

CuInTe2 다결정은 수평전기로에서 합성하고, CuInTe2 단결정은 수직 Bridgman 방법으로 성장하여 결정구조를 조사하고, Hall 효과를 30K에서 293K의 온도영역에서 측정하였다. CuInTe2 다결정 및 단결정은 정방정계였다. 다결정의 격자상수는 a=6.168Å, c=12.499Å 그리고 c/a=2.026이었고, 단결정의 격자상수는 a=6.186Å, c=12.453Å, 그리고 c/a=2.013이었다. CuInTe2 단결정의 성장면은 Laue 배면반사 사진으로부터 구하였으며 (112)면이었다. CuInTe2 단결정의 Hall 효과는 van der Pauw 방법으로 측정하였다. 상온에서 측정된 c축에 수직한 시료의 운반자농도 p는 2.14×1023holes/m3, 전기전도도 δ는 739.58Ω-1m-1 그리고 이동도 μ는 2.16×10 m2/V·s 이었다. c축에 평행한 시료의 운반자농도 p는 1.51×1023holes/m3, 전기전도도 σ는 717.55Ω-1m-1 그리고 이동도 μ는 2.97×10-2 m2/V·s이었다. c축에 수직 및 평행한 시료의 Hall계수가 양의 값이어서 CuInTe2 단결정은 p형 반도체임을 알 수 있었다. 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.

C.V.D. 방법에 의한 Cd_0.78Zn_0.22 S박막 성장과 광전기적 특성연구

유상하,이상렬,홍광준,서상석,김혜숙,전승룡,윤은희,문종대 조선대학교 기초과학연구소 1993 自然科學硏究 Vol.16 No.1

We had grown Cd_0.78Zn_0.22S polycrystal thin films on slide substrate using chemical vapour deposition(CVD) method. We measured X-ray diffraction patterns in order to study Cd_0.78Zn_0.22S polycrystal structure. We studied its band gap using transmission curves and photocurrent and also analyzed photoluminescence using configurational coordinate model. We measured Hall effect·on this sample by Van der Pauw method and studied on carrier density and mobility depending on temperature.

Hot Wall Epitaxy(HWE)법에 의한 MnAl₂S₄ 단결정 박막 성장과 광전도 특성

유상하,이기정,홍광준,문종대,You, Sangha,Lee, Kijeong,Hong, Kwangjoon,Moon, Jongdae 한국결정성장학회 2014 韓國結晶成長學會誌 Vol.24 No.6

수평 전기로에서 $MnAl_2S_4$ 다결정을 합성하여 HWE(Hot Wall Epitaxy)방법으로 $MnAl_2S_4$ 단결정 박막을 반절연성 GaAs(100)기판에 성장시켰다. $MnAl_2S_4$ 단결정 박막의 성장 조건은 증발원의 온도 $630^{\circ}C$, 기판의 온도 $410^{\circ}C$였고 성장 속도는 $0.5{\mu}m/hr$였다. 이때 $MnAl_2S_4$ 단결정 박막의 결정성의 조사에서 이중결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)도 132 arcsec로 가장 작아 최적 성장 조건임을 알 수 있었다. $MnAl_2S_4$/SI(Semi-Insulated) GaAs(100) 단결정 박막의 광흡수를 293 K에서 10 K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap $E_g(T)$는 Varshni 공식에 따라 계산한 결과 $E_g(T)=3.7920eV-(5.2729{\times}10^{-4}eV/K)T^2/(T+786K)$였다. $MnAl_2S_4$ 단결정 박막의 응용소자인 photocell로 사용할 수 있는 pc/dc 값이 가장 큰 광전도셀은 S 증기분위기에서 열처리한 셀로 $1.10{\times}10^7$이었으며, 광전도 셀의 감도(sensitivity)도 S 증기분위기에서 열처리한 셀이 0.93로 가장 좋았다. 또한 최대 허용소비전력(MAPD)값도 S 증기분위기에서 열처리한 셀이 316 mW로 가장 좋았으며, S 증기분위기에서 열처리한 셀의 응답시간은 오름시간 14.8 ms, 내림시간 12.1 ms로 가장 빠르게 나타나, $MnAl_2S_4$ 단결정 박막을 S 분위기에서 $290^{\circ}C$로 30분 열처리한 photocell이 상용화가 가능할 것으로 여겨진다. A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ 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 $630^{\circ}C$ 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 temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

$CuInTe_2$ 단결정 성장과 특성연구(II)

유상하,홍광준,이상렬,신용진,이관교,서상석,김승욱,정준우,신영진,정태수,신현길,김택성,문종대,You S.H.,Hong K.J.,Lee S.Y.,Shin Y.J.,Lee K.K.,Suh S.S.,Kim S.U.,Jeong J.W.,Shin Y.J.,Jeong T.S.,Shin B.K.,Kim T.S.,Moon J.D. 한국결정학회 1997 韓國結晶學會誌 Vol.8 No.1

[ $CuInTe_2$ ] 다결정은 수평전기로에서 합성하고, $CuInTe_2$ 단결정은 수직 Bridgman 방법으로 성장시켰다. $CuInTe_2$ 단결정의 c축에 수직 및 평행한 시료의 광전도도와 광발광특성을 293K에서 20 K의 온도영역에서 측정하였다. 측정된 광전류 봉우리로부터 구한 c축에 수직 및 평행한 시료의 에너지 띠 간격은 상온에서 각각 0.948 eV와 0.952 eV였다. 광전류 봉우리와 광발광 봉우리의 에너지차는 포논에너지이며 상온에서 c축에 수직 및 평행한 시료의 에너지차는 각각 22.12 meV와 21.4 meV였다. 또한 광전류 스펙트럼으로부터 시료의 spin-orbit 상호작용과 결정장 상호작용에 의한 가전자대의 갈라짐 ${\Delta}cr$과 ${\Delta}so$는 각각 0.046, 0.014 eV였다. [ $CuInTe_2$ ] synthesised in a horizontal electric furnace was found to be polycrystalline. Single crystals of $CuInTe_2$ were grown with the vertical Bridgman technique. The photoconductivity and photoluminescence of the crystals were measured in the temperature range 20 to 293 K. From the photocurrent peaks measured for the samples both perpendicular and parallel to c-axis, the energy band gaps of the samples were found to be 0.948 eV and 0.952 eV at room temperature respectively. The energy difference of the photocurrent and photoluminescence peaks of the samples both perpendicular and parallel to the c-axis measured at room temperature was a phonon energy, and its values were 22.12 meV and 21.4 meV respectively. The splitting of the valence band due to spin-orbit and crystal field interaction was calculated from the photocurrent spectra of the samples, The ${\Delta}cr\;and\;{\Delta}so$ are 0.046,0.014 eV respectively.

Optical and Structural Properties for CuInSe2 Epilayers Grown by Using Hot Wall Epitaxy

유상하,홍광준,이봉주,방진주,정태수,Changju Youn 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.6

Copper indium diselenide (CuInSe$_2$, CIS) layers were grown on GaAs(100) substrates by using the hot wall epitaxy (HWE) method. The optimum temperatures of the substrate and the source for the growth turned out to be 410 and 620 $^\circ$C, respectively. The CIS layers were epitaxially grown along the $<$112$>$ direction and kept the initial mole fraction during the layer growth. Based on the absorption measurement, the band-gap variation of CIS was well interpreted by Varshni's equation. However, the energy difference, 180 meV, of the band gap between liquid helium and room temperatures was a very large value, unlike that of the reported CIS. Also, from the low-temperature photoluminescence measurement, the acceptor impurities in the CIS layers were confirmed to be native defects of V$_{\rm Cu}$ and/or Se$_{int}$, which were deeply located at 73.8 meV above the edge of the valence band

p-PbSe/n-Si Heterojunction 태양전지에 대한 연구

柳相河,李在連 조선대학교 기초과학연구소 1987 自然科學硏究 Vol.10 No.1

Heterojunction solar cell of p-PbSe/n-Si fabricated by solution growth technique at room temperature. The crystal structure, spectral response, surface morphology, and I - V characteristics of p-PbSe/n-Si heterojunction are studied. The PbSe/n-Si layer deposited on a silicon substrate (400) were found to be cubic structure with crystal orientation (400), (220), (200), and (111) from the X-ray diffraction patterns. The open-circuit voltage, short-circuit current, fill factor, and conversion efficiency of p-PbSe/n-Si heterojunction solar cell under 80Mw/㎠ illumination were found to be 0.41V, 21mA, 0.73, and 6.285%, respectively.

n-CdS_(0.46)Se_(0.54)/p-Cu_92-x)S_(0.46)Se_(0.54) 이종접합 태양전지의 제작과 그 특성에 관한 연구

유상하,최승평,이상열,홍광준,서상석,김혜숙,전승룡,윤은희,문종대,신영진,정태수,신현길,김택성,유기수 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

승화방법에 의해 CdS_0.46Se_0.54 단결정을 성장하여 결정구조를 조사하고, Van der Pauw 방법으로 Hall effect를 측정하여 carrier density의 온도 의존성과 mobility의 온도 의존성을 조사하였다. 성장된 CdS_0.46Se_0.54 단결정을 치환반응하여 n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 이종접합 태양전지를 제작하였다. Spectral response, 전류-전압특성 및 전력변환 효율을 조사하여 그 결과로부터 개방전압은 0.48V, 단락 전류 밀도는 21mA/㎠, fill factor와 전력변환효율은 각각 0.75와 9.5%를 얻었다. CdS_0.46Se_0.54 single crystal was grown by a sublimation method. The crystal structure and the temperature dependence of carrier density and mobility of CdS_0.46Se_0.54 single crystal were studied. Heterojunction solar cells on n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 were fabricated by the substitution reaction. The spectral response, the J-U characteristics and the conversion efficiency of the n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells were studied. The open-cricuit voltage, short-circuit density, fill factor and conversion efficiency of n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells under 80mW/㎠ illumination were found to be 0.48V, 21mA/㎠, 0.75 and 9.5%, respectively.