• Title/Summary/Keyword: Window Layer

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Effects of Substrate Temperature on the Microstructure and Photoluminescence Properties of ZnO Thin Films by Atomic Layer Deposition (ZnO 성장을 위한 Atomic Layer Deposition법에서 공정온도가 박막의 구조적 및 광학적 특성에 미치는 영향)

  • Lim, Jong-Min;Lee, Chong-Mu
    • Korean Journal of Materials Research
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    • v.15 no.11
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    • pp.741-744
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    • 2005
  • Atomic layer deposition (ALD) is a very promising deposition technique for ZnO thin films. However, there have been very few reports on ZnO grown by ALD. Effects of substrate temperature in both ALD and post annealing on the microstructure and PL properties of ZnO thin films were investigated using X-ray diffraction, photoluminescence, and scanning electron microscopy. The temperature window of ALD is found to be between $130-180^{\circ}C$. The growth rate of ZnO thin film increases as the substrate temperature increases in the temperature range except the temperature window. The crystal quality depends most strongly on the substrate temperature among all the growth parameters of ALD. The crystallinity of the film is improved by increasing the growth thine per ALD cycle or doing post-annealing treatment. The grain size of the film tends to increase and the grain shape tends to change from a worm-like longish shape to a round one as the annealing temperature increases from $600^{\circ}C\;to\;1,000^{\circ}C$.

Advanced Real-Time Rate Control for Low Bit Rate Video Communication

  • Kim, Yoon
    • Journal of the Korea Computer Industry Society
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    • v.7 no.5
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    • pp.513-520
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    • 2006
  • In this paper, we propose a novel real-time frame-layer rate control algorithm using sliding window method for low bit rate video coding. The proposed rate control method performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. A new frame-layer rate-distortion model is derived, and a non-iterative optimization method is used for low computational complexity. In order to reduce the quality fluctuation, we use a sliding window scheme which does not require the pre-analysis process. Therefore, the proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder. Experimental results indicate that the proposed control method provides better visual and PSNR performance than the existing TMN8 rate control method.

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A Study on the Electrical and Optical Properties of CdS Thin Film by Annealing for Solar Cell (태양전지용 CdS 박막의 열처리에 따른 전기 및 광학적 특성에 관한 연구)

  • Park, Jung-Cheul;Chu, Soon-Nam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.11
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    • pp.999-1003
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    • 2009
  • In this paper, CdS thin films well-known to window layer for solar cell were fabricated by means of vacuum evaporation method treated with different substrate heating. During film fabrication the substrates were heated at 50, 75 and $100^{\circ}C$, respectively. The thin films were then annealed at $200^{\circ}C$ in atmosphere, and the electrical and optical properties were investigated. By annealing, the hexagonal structure of films was changed into cubic structure. Their transmissivity was also increased and moved to longer wave band. It was shown that the film fabricated with the substrate heat-treated at $50^{\circ}C$ had the lowest resistivity.

Rapid Thermal Annealing of Silicon on Insulator (SOI) with a W-Halogen Lamp (텅스텐 할로겐 램프에 의한 절연층 상의 실리콘)

  • 김춘근;김용태;민석기
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.8
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    • pp.950-958
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    • 1988
  • We have implemented a RTA system using W-halogen lamps and tried to recrystallize the phosphorus ion implanted amorphous silicon on insultor (SOI) taking advantages of seeding window. The purpose of this study is to investigate the possibility of a typical crystalline orientation occurred during the solidifying process of molten amorphous silicon layer. Experimental results show that several twin boundaries are found on the seeding window region after annealing for 15 sec at 1040\ulcorner. These twin boundaries represent that the recrystallization is partialy possible and when the annealing is done at 1150\ulcorner, (100) etch pits with <110> facets are found on the solidified amorphous silicon layer. Consequently, Hall mobility of recrystallized silicon film is measured and the thermal behavior of grain boundary is also observed by SEM.

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Electrical and Optical Properties of CdS Thin Film with Different Substrate Temperatures (CdS 박막의 기판온도 변화에 따른 전기 및 광학적 특성)

  • Park, Jung-Cheul;Lee, Woo-Sik;Chu, Soon-Nam;Cho, Yong-Joon;Jeon, Yong-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.9
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    • pp.792-797
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    • 2009
  • In this paper, CdS thin films for the use of window layer in solar cell were fabricated by vacuum evaporation method to improve the reproducibility, The electrical and optical properties of thin films with the variations of substrates temperature and the variations of the film thickness were investigated. As increasing the substrates temperature the resistivities of films were increased. The samples transmissivity were shown over 70% when the wavelength were above 500 nm. In the films with 280 nm thickness, its transmissivity were reached 100%. The resistivities of the samples were decreased as increasing its thickness.

Effect of Reaction Temperature on Properties of CdS Thin Films Prepared by Chemical Bath Deposition (화학적으로 증착된 CdS 박막의 반응온도에 따른 물성)

  • Song, Woo-Chang
    • Journal of the Korean institute of surface engineering
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    • v.38 no.3
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    • pp.112-117
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    • 2005
  • In this paper, CdS thin films, which were widely used as a window layer of the CdS/CdTe and the $CdS/CuInSe_2$heterojunction solar cell, were grown by chemical bath deposition, and the structural, optical and electrical properties of the films on reaction temperatures were investigated. Cadmium acetate and thiourea were used as cadmium and sulfur source, respectively. And Ammonium acetate was used as the buffer solution. As the reaction temperatures were increased, the deposition rate of CdS fllms prepared by CBD was increased and the grain size was large due to increasing reaction rate in solution, also optical transmittance of the films in visible lights was increased on rising reaction temperatures.

Electrochemical Preparation of Indidum Sulfide Thin Film as a Buffer Layer of CIGS Solar Cell (CIGS 태양전지 버퍼층으로의 활용을 위한 인듐설파이드의 전기화학적 합성)

  • Kim, Hyeon-Jin;Kim, Kyu-Won
    • Journal of the Korean Electrochemical Society
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    • v.14 no.4
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    • pp.225-230
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    • 2011
  • CIGS solar cells are kind of thin film solar cells, which are studied several years. CdS buffer layer that makes heterojunction between window layer and absorbing layer was one of issue in the CIGS solar cell study. New types of buffer layer consisted of indium sulfide are being studied these days owing to high price and environmental harmful of CdS. In this study, we demonstrated electrochemical synthesis of indium sulfide film as a buffer layer, which is cheaper and faster than other methods. A uniform indium sulfide film was obtained by applying two different alternating potentials. The band gap of the film was optimized by controlling temperature during the electrochemical synthesis. Using x-ray photoelectron spectroscopy and diffraction method we confirmed that ${\beta}$-indium sulfide was formed on ITO electrode surface.

Sound Absorption Performance of Korean Traditional Window Papers (창호지의 흡음성능에 관한 실험적 연구)

  • Choi, Eun-Seok;Lee, Tai-Gang;Kim, Hang;Kim, Sun-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.17-20
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    • 2006
  • Korean traditional houses have been developed in sympathy with natural environment and formed comfortable indoor condition by properly using surrounding natural resources including building layout, space construction and material our traditional wooden windows adjusting ambient temperature and humidity have both the functions of window and door, although they are clearly divided in the West. While window paper is attached from the outside in China and Japan, it is attached from the inside in Korea. The opening and closing mode of windows is similar and their dimensions are shown not to he standardized but diverse in terms of the characteristic of wooden furniture and that of components placed between columns. Thus this study is to look into the performance of band-lattice door of a typical traditional one by observing changes in sound absorption characteristics according to difference in thickness and finishing method of window paper and those in sound absorption characteristics with the changed thickness of air layer in traditional windows and doors.

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Electrical and Optical Properties of Vacuum-Evaporated CdS Films for the Window Layer of $CdS/CuInSe_2$ Solar Cells. ($CdS/CuInSe_2$태양전지의 Window Layer로 쓰이는 CdS박막의 진공증착법에 따른 전기적.광학적 성질)

  • Nam, Hee-Dong;Lee, Byung-Ha;Park, Sung
    • Korean Journal of Crystallography
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    • v.8 no.2
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    • pp.105-110
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    • 1997
  • 1μm-CdS films for a window layer of CdS/CuInSe2 solar cell have been prepared by vacuum of 1x10-3 mTorr. Source and substrate temperature ranges were used 800-1100'C and 50-200℃ respectively. Structural, electircal and optical properties of CdS films have been investigated by X-ray diffractometer (XRD), scanning electron microscopy (SSEM), electrical resistivity, the Hall measurement and optical transmission spectra. Electrical resistivity and optical transmission of the CdS films decreased with the increase in CdS source temperature without substrate heating. All the films had hexagonal structure and strong texture with (002) orientation of grain normal to the substrate glass. CdS films evaporated at 1000℃ were the highest electrical conductivity of 0.9(S/cm). Electrical resistivity and optical transmission at the substrate temperature of 100℃ were 40(Ω,cm) and 80% respectively.

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