• Title/Summary/Keyword: surface textured

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Analysis on the Optical Properties and Fabrication of Textured AZO Thin Films for Increasing the Efficiency of LED (LED 효율 향상을 위한 Texture구조 AZO 박막의 제조와 광학적 특성분석)

  • Kim Kyeong-Min;Jin Eun-Mi;Park Choon-Bae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.10
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    • pp.901-906
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    • 2006
  • The transparent conductive oxide(TCO) has been used in necessity as front electrode for increasing efficiency of LED. In our paper, aluminium-doped zinc oxide films(AZO), which has transparent conducting were prepared with RF magnetron sputtering system on glass substrate(corning 1737) and annealed at $400^{\circ}C$ for 2 hr in vacuum ambient and $600^{\circ}C$ for 2hr with $O_2$ ambient respectively. The smooth AZO films were etched in diluted HCL(0.5 %) to examine the surface properties, which in ambient post-annealing process. We confirmed that the electric, structural and optical properties of textured AZO thin films, which implemented using the methods of XRD, FWHM, AFM and Hall measurement. The properties of textured AZO thin films especially depended on the ambient post-annealing process. We presumed that the change of transmittances as R G B LED and the ambient post-annealing process will be increasing the efficiency of LED.

Deposition of $CeO_2$ buffer layer for YBCO coated conductors on biaxially textured Ni substrate by MOCVD technique (양축 정렬된 Ni기판 위에 MOCVD법에 의한 YBCO 초전도 선재용 $CeO_2$ 완충층의 증착)

  • 김호진;주진호;전병혁;정충환;박순동;박해웅;홍계원;김찬중
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.2
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    • pp.21-26
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    • 2002
  • Textured CeO2 buffer layers for YBCO coated conductors were deposited on biaxially textured Ni substrate by metalorganic chemical vapor deposition (MOCVD). The degree of texture of deposited $CeO_2$ films was strong1y dependent on the deposition temperature (Td) and oxygen Partial Pressure(PO2). ($\ell$00) textured $CeO_2$ films were well deposited at T=500~52$0^{\circ}C$. PO2=0.90~3.33 Torr. The surface morphology showed that the films consisted of columnar CeO2 films grown from the Ni substrates. The root mean square roughness of CeO$_2$ films estimated by atomic force microscopy(AFM) increased as the deposition temperature(Td) increa- sed. The growth rate of the $CeO_2$ films deposited at T=52$0^{\circ}C$ and PO2=2.30 Torr was 150~200 nm/min that was much faster than that of other Physical deposition methods.

Fabrication of Double Textured Selective Emitter Si Solar Cell Usning Electroless Etching Process (이중 텍스쳐 구조를 적용한 선택적 에미터 태양전지의 특성 분석)

  • Kim, Changheon;Lee, Jonghwan;Lim, Sangwoo;Jeong, Chaehwan
    • Current Photovoltaic Research
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    • v.2 no.3
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    • pp.130-134
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    • 2014
  • We have fabricated the selective emitter solar cell using double textured nanowires structure. The $40{\times}40mm2$-sized silicon substrates were textured to form the pyramid-shaped surface and the nanowires were fabricated by metal assisted chemical etching process using Ag nanoparticles, subsequently. The heavily doped and shallow emitters for selectiv eemitter solar cells were prepared through the thermal $POCl_3$ diffusion and chemical etch-back process, respectively. The front and rear electrodes were prepared following conventional screen printing method and the widths of fingers have been optimized. The selective emitter solar cell using double textured nanowires structure achieved a conversion efficiency of 17.9% with improved absorption and short circuit current density.

Melt Textured Growth and Superconducting Properties of RE3+ Elements Doped YBCO Superconductors (RE3+원소가 첨가된 YBCO고온초전도체의 용융성장 및 초전도 특성)

  • 김소정
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.231-237
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    • 2003
  • RE(Nd, Sm) elements doped (RE/Y)$_{1.8}$B $a_{2.4}$C $u_{3.4}$$O_{7-x}$ [(RE/Y)1.8] high $T_{c}$ superconductors were directionally grown by Top Seed Melt Growth(TSMG) process in air atmosphere. The (001)melt-textured N $d_{1.8}$B $a_{2.4}$C $u_{3.4}$ $O_{7-X}$(Nd1.8) seed crystals were used for achieving the c-axis alignment large grains perpendicular to surface of the samples. The (RE/Y)1.8 SEM micrographs of the melt-textured (RE/Y)1.8 samples revealed that the nonsuperconducting (RE/Y)211 inclusions are uniformly distributed in the superconducting (RE/Y)123 matrix except the region very close to the Nd seed crystal. The microstructure and superconducting properties were investigated by XRD, SEM, TEM and SQUID magnetometer. The Melt-textured (RE/Y)1.8 samples showed an onset $T_{c}$=91K and sharp superconducting transition. Also, the magnetization value of the (RE/Y)1.8 samples were compared with those of Y1.8 sample at 77 K. 77 K. 77 K. 77 K.K.

Smooth versus Textured Tissue Expanders: Comparison of Outcomes and Complications in 536 Implants

  • Omar Allam;Jacob Dinis;Mariana N. Almeida;Alexandra Junn;Mohammad Ali Mozaffari;Rema Shah;Lauren Chong;Olamide Olawoyin;Sumarth Mehta;Kitae Eric Park;Tomer Avraham;Michael Alperovich
    • Archives of Plastic Surgery
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    • v.51 no.1
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    • pp.42-51
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    • 2024
  • Background Increasing concerns regarding the safety of textured surface implants have resulted in surgeons transitioning from textured tissue expanders (TEs) to smooth TEs. Given this change has only recently occurred, this study evaluated outcomes between smooth and textured TEs. Methods Women who underwent two-stage breast reconstruction using TEs from 2013 to 2022 were included. TE-specific variables, perioperative information, pain scores, and complications were collected. Chi-squared, t-test, and linear regression analyses were performed. Results A total of 320 patients received a total of 384 textured and 152 smooth TEs. Note that 216 patients received bilateral reconstruction. TEs were removed in 9 cases. No significant differences existed between groups regarding comorbidities. Smooth TEs had a higher proportion of prepectoral placement (p < 0.001). Smooth TEs had less fills (3±1 vs. 4±2, p < 0.001), shorter expansion periods (60±44 vs. 90±77 days, p < 0.001), smaller expander fill volumes (390±168 vs. 478±177 mL, p < 0.001), and shorter time to exchange (80±43 vs. 104±39 days, p < 0.001). Complication rates between textured and smooth TEs were comparable. Smooth TE had a greater proportion of TE replacements (p = 0.030). On regression analysis, pain scores were more closely associated with age (p = 0.018) and TE texture (p = 0.046). Additional procedures at time of TE exchange (p < 0.001) and textured TE (p = 0.017) led to longer operative times. Conclusion As many surgeons have transitioned away from textured implants, our study shows that smooth TEs have similar outcomes to the textured alternatives.

Texturing of Multi-crystalline Silicon Using Isotropic Etching Solution (등방성 에칭용액을 이용한 다결정 실리콘의 표면조직화)

  • Eum, Jung-Hyun;Choi, Kwan-Young;Nahm, Sahn;Choi, Kyoon
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.685-688
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    • 2009
  • Surface Texturing is very important process for high cell efficiency in crystalline silicon solar cell. Anisotropic texturing with an alkali etchant was known not to be able to produce uniform surface morphology in multi-crystalline silicon (mc-Si), because of its different etching rate with random crystal orientation. In order to reduce surface reflectance of mc-Si wafer, the general etching tendency was studied with HF/HN$O_3$/De-ionized Water acidic solution. And the surface structures of textured mc-Si in various HF/HN$O_3$ ratios were compared. The surface morphology and reflectance of textured silicon wafers were measured by FE-SEM and UVvisible spectrophotometer, respectively. We obtained average reflectance of $16{\sim}19$% for wavelength between 400 nm and 900 nm depending on different etching conditions.

Study on the Evolution of Sand Structure during Shearing (전단시험 중 모래입자의 변형에 관한 연구)

  • 이석원
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.289-296
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    • 2000
  • This paper summarizes the results of a study which has quantified the evolution of the structure of sands adjacent to geomembranes of varying roughness at different stages of shearing. The results show that the structure evolution, and hence shear mechanisms for rounded uniform sands adjacent to geomembranes, are directly influenced by the surface roughness of the geomembranes. For smooth geomembranes, the shear mechanism predominantly involves sliding of sand particles and only affects the sand structure within two particle diameters of the geomembrane. For slightly textured geomembranes, the effects of interlocking and dilation of sand particles extends the zone of evolution to four particles diameters from the interface. For moderately/heavily textured geomembranes, the interlocking and dilation of sand particles is fully developed and results in large dilation in the interfacial zone, which extends up to six particle diameters from the interface. By understanding how the structure of the sand adjacent to geomembranes of different roughness changes during shearing, it may be possible to identify alternative geomembrane roughening procedures and patterns that can lead to more efficient interface designs.

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Remote HF PECVD 공정을 이용한 Textured ZnO 박막증착 Deposition of textured ZnO thin film by using remote HF PECVD

  • Jeong, Hyeon-Yeong;Jeong, Yong-Ho;Chu, Won-Il;Gwon, Seong-Gu
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2009.05a
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    • pp.97-97
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    • 2009
  • 원격 고주파 원도결합 플라즈마 증착공정을 이용하여 태양광의 반사도를 낮추고, 흡수효율을 개선할 수 있는 피라미드형 표면구조를 가지느니 투명전동성 ZnO 박막을 높은 증착속도로 증착할 수 있는 공정조건을 찾기 위하여 반응압력, $H_{2}O$/DEZn 유량비, 플라즈마 출력과 기판온도에 대하여 실험하였다. 실험결과 400$\sim$600nm/min 이상의 높은 증착속도을 얻을 수 있었으며, 넓은 공정 영역에서 안정적인 피라미드 표면 구조를 가지는 공정조건을 확보하였다. 증착된 박막의 표면구조와 물분석 결과와 공정조건과의 관계에 대한 연구 결과를 발표할 예정이다.

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Transaxillary Endoscopic Breast Augmentation

  • Sim, Hyung-Bo
    • Archives of Plastic Surgery
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    • v.41 no.5
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    • pp.458-465
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    • 2014
  • The axillary technique is the most popular approach to breast augmentation among Korean women. Transaxillary breast augmentation is now conducted with sharp electrocautery dissection under direct endoscopic vision throughout the entire process. The aims of this method are clear: both a bloodless pocket and a sharp non-traumatic dissection. Round textured or anatomical cohesive gel implants have been used to make predictable welldefined inframammary creases because textured surface implants demonstrated a better stability attributable to tissue adherence compared with smooth surface implants. The axillary endoscopic technique has greatly evolved, and now the surgical results are comparable to those with the inframammary approach. The author feels that this technique is an excellent choice for young patients with an indistinct or absent inframammary fold, who do not want a scar in the aesthetic unit of their chest.

Tribological Performance of Laser Textured Translucent Duplex α/β-Sialon Composite Ceramics

  • Joshi, Bhupendra;Tripathi, Khagendra;Gyawali, Gobinda;Lee, Soo Wohn
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.180-181
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    • 2014
  • Optically translucent Sialon ceramics was fabricated by hot pressed sintering method. The Sialon ceramics was laser textured and their tribological performance was observed. Starved lubrication method was applied on Sialon ceramics with different dimple spacing under a load of 10N and at room temperature. The material having high dimple spacing ($200{\mu}m$) shows low coefficient of friction. The material shows mild wear and therefore, wear rate of steel ball (meeting partner) was observed to measure wear rate. Different phases Sialon ceramics were analyzed by XRD patterns. Moreover, the mechanical properties of the Sialon ceramics were observed.

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