• 태양에너지
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• 제10권2호
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• pp.59-68
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• 1990

본 논문에서는 진공증착법으로 순수한 CdSe박막과 미소량의 불순물을 첨가한, CdSe 박막을 제작하고, 그후 제작한 박막을 진공중에서 열처리하여 광도전성 박막으로서의 특성을 조사하였다. 증착시 기판의 온도는 $200^{\circ}C$이고 열처리 온도는 $400^{\circ}C$에서 $600^{\circ}C$에 걸쳐 행하였다. 일반적으로 박막의 광도전성은 열처리 온도가 높을수록 향상된다. 제작된 각 시편의 광전류는 조도의 증가에 따라 직선적인 관계가 나타난다. 제작된 각 시편에 대하여 파장범위 380-850nm에서 광도전특성을 조사한 결과 광응답의 최대치는 700nm 부근이며 불순물을 첨가함에 따라 장파장쪽으로 이동한다. 순수한 CdSe 박막의 경우 $240^{\circ}K$ 부근에서 양호한 광응답 특성이 나타나나 불순물 첨가의 경우에는 온도가 상승함에 따라 양호한 특성이 나타난다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.81-82
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• 2007

The stochiometric mix of evaporating materials for the $CdGa_2Se_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CdGa_2Se_4$ 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 $630^{\circ}C\;and\;420^{\circ}C$, respectively. After the as-grown single crystal $CdGa_2Se_4$ thin films were annealed in Cd-, Se-, and Ga -atmospheres, the origin of point defects of single crystal $CdGa_2Se_4$ thin films has been investigated by PL at 10 K. The native defects of $V_{Cd},\;V_{Se},\;Cd_{int},\;and\;Se_{int}$ obtained by PL measurements were classified as donors or acceptors. And we concluded that the heat-treatment in the Cd-atmosphere converted single crystal $CdGa_2Se_4$ thin films to an optical p-type. Also, we confirmed that Ga in $CdGa_2Se_4$/GaAs did not form the native defects because Ga in single crystal $CdGa_2Se_4$ thin films existed in the form of stable bonds.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.939-942
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• 2008

Photoelectrochemical deposition of CdZnSe thin films on the Se-modified Au electrode using electrochemical quartz crystal microgravimetry (EQCM) and voltammetry is described. Corrosion of pre-deposited Se electrodes by illumination at a fixed potential resulted in $Se^{2-}$ species, which was manifest from the EQCM frequency changes. $Se^{2-}$ species generated from the photocorrosion reacted with $Cd^{2+}$ and $Zn^{2+}$ ions in the electrolyte to form CdZnSe films on the Au electrode. The effect of electrolyte composition on the composition and band gap of CdZnSe films was studied in detail. Also, photoelectrochemistry, EDX, Raman spectroscopy were used for the characterization of CdZnSe thin films.

• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.776-781
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• 2010

CdSe films were deposited on glass substrates (CdSe/glass) by thermal evaporation. Substrate temperature was lowered by cooling substrate holder with liquid nitrogen. Substrate temperatures were $200^{\circ}C$, $0^{\circ}C$ and $-40^{\circ}C$. The crystallographic properties and surface morphologies of the CdSe/glass films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical and electrical properties of the films were investigated by dependence of energy gap, photosensitivity and resistivity on the substrate temperature. CdSe/glass showed energy gap of ~1.72 eV regardless of substrate temperature. The resistivity of the films decreased to $0.5{\Omega}cm$ by lowering the substrate temperature to $-40^{\circ}C$. The CdSe/glass films prepared at $0^{\circ}C$ showed the highest photosensitivity among the films in this study.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.502-506
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• 2012

In order to find the structural characteristics of the thin films of group II-VI semiconductor compounds compared with those of powder materials, films were made of 4 powders of ZnS, CdS, CdSe, and CdTe(Aldrich), each with 99.99 % purity. For the ZnS/CdS multi-layers, the ZnS layer was coated over the CdS layer on an $AlO_x$ membrane, which served as a protective layer within a vacuum at the average speed of 1 ${\AA}$/sec. After studying the structures of the group II-VI semiconductor thin films by using X-ray spectroscopy, we found that the ZnS, ZnS/CdS, CdS, and CdSe films were hexagonal and exhibited some degree of preferred orientation. Also, the particles of the thin films of II-VI semiconductor compounds proved to be more homogeneous in size compared to those of the powder materials. These results were further verified through scanning electron microscopy(SEM), EDX analysis, and powder and thin film X-ray diffraction.

• 대한전자공학회논문지
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• 제21권5호
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• pp.7-10
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• 1984

일반적으로 단결정반도체시편에서는 그의 자유반송자 밀도값이 측정방법을 달리해도 일정하다. 그러나 CdSe 박막반도체의 자유반송자 밀도간은 측정방법을 달리했을 때 다르게 나타난다. 본 연구에서는 C-V방법, Seebeck 효과 및 a. c. Hall 효과를 통해서 측정한 CdSe 박막반도체의 자유반송자가 1018/㎤∼1024㎤범위의 값을 나타냈다. 이들 값의 차이를 나타내는 원인을 논의하고자 한다.

• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.829-838
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• 2007

The stochiometric mix of evaporating materials for the $CdGa_2Se_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CdGa_2Se_4$ 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 $630^{\circ}C$ and $420^{\circ}C$, respectively. 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 of $CdGa_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $8.27{\times}10^{17}\;cm^{-3},\;345\;cm^2/V{\cdot}s$ at 293 K. respectively. The temperature dependence of the energy band gap of the $CdGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $Eg(T)\;=\;2.6400\;eV\;-\;(7.721{\times}10^{-4}\;eV/K)T^2/(T+399\;K)$. After the as-grown single crystal $CdGa_2Se_4$ thin films were annealed in Cd-, Se-, and Ga -atmospheres, the origin of point defects of single crystal $CdGa_2Se_4$ thin films has been investigated by PL at 10 K. The native defects of $V_{Cd}$, $V_{Se}$, $Cd_{int}$, and $Se_{int}$ obtained by PL measurements were classified as donors or accepters. We concluded that the heat-treatment in the Cd-atmosphere converted single crystal $CdGa_2Se_4$ thin films to an optical p-type. Also, we confirmed that Ga in $CdGa_2Se_4/GaAs$ did not form the native defects because Ga in single crystal $CdGa_2Se_4$ thin films existed in the form of stable bonds.

• 센서학회지
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• 제1권1호
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• pp.53-57
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• 1992

본 연구는 $CdS_{1-x}Se_{x}$의 박막을 제작하고 그 전기-광학적인 특성을 조사한 것이다. 전자선 가열증착법을 이용하여 $CdS_{1-x}Se_{x}$을 알루미나 기판위에 $1.5{\times}10^{-7}$ torr의 압력, 4kV의 전압, 2.5 mA의 전류 그리고 기판온도를 $300^{\circ}C$로 유지하여 증착하였다. 증착된 $CdS_{1-x}Se_{x}$ 박막은 X-ray 회절 실험을 통하여 볼 때, 육방정계의 결정구조를 가지며 성장되었다. $CdS_{1-x}Se_{x}$ 도전막은 특정분위기에서 $550^{\circ}C$, 30분간 열처리함으로써 높은 광전도성을 나타내게 되었다. 또한 Hall 효과, 광전류 스펙트럼, 감도, 최대 허용 전력과 응답시간 등을 조사하였다.

• 한국진공학회지
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• 제9권1호
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• pp.60-68
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• 2000

The optical constants ($E_g^d$, n, K) of the polycrystalline CdSe thin films deposited on the glass substrate by the electron-beam evaporation technique are determined over 400~2,500 nm photon wavelengths. In order to explain the variation of the optical contents with film thickness and substrate temperatures, the surface microstructural parameter are investigated by AFM (atomic forced microscope( images for the films deposited by different growth conditions. It is shown that the variations of optical constants are close related to changes of the surface morphology of the CdSe thin films. The decrease in the band gap with film thickness is connected with quantum size effects due to increase of the grain size. The refractive index of CdSe films decrease with increasing the grain size of the films, and the dispersion of the refractive index followed a single oscillator model according to the Sellmeier formulation.

• 한국진공학회지
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• 제18권6호
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• pp.459-467
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• 2009

진공증착법으로 $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막을 ITO(indium tin oxide) 유리 기판 위에 제작하였다. 결정화는 증착된 박막들을 질소분위기의 전기로에서 열처리함으로서 이룰 수 있었다. X-선 회절 분석에 의하여 증착된 $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막의 격자상수는 $a\;=\;7.405\;{\AA}$, $c\;=\;36.240\;{\AA}$와 $a\;=\;7.43\;{\AA}$, $c\;=\;36.81\;{\AA}$로서 능면체(rhombohedral) 구조이었고, 열처리 온도를 증가함에 따라 (113)방향으로 선택적으로 성장됨을 알 수 있었다. 열처리 온도를 증가시킴에 따라 입계 크기가 점차 커지고 판상구조로 결정화 되었다. 실온에서 측정한 광학적인 에너지 띠 간격은 열처리 온도의 증가에 따라 $Cd_2GeSe_4$ 박막의 경우 1.70 eV ~ 1.74 eV로 증가하였고, $Cd_2GeSe_4:Co^{2+}$ 박막의 경우 1.79 eV ~ 1.74 eV로 감소하였다. $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막 내의 전하운반자들의 동역학적 거동을 광유기 방전 특성(PIDC : photoinduced discharge characteristics) 방법으로 조사하였다.