• Title/Summary/Keyword: surface textured

Search Result 297, Processing Time 0.026 seconds

A Study on Shape from Patterns (3차원 물체의 형상 인식에 관한 연구)

  • Kim, Do-Nyun;Cho, Dong-Sub
    • Proceedings of the KIEE Conference
    • /
    • 1990.07a
    • /
    • pp.542-545
    • /
    • 1990
  • Texture provides an important source of information about the local orientation of visible surfaces. In this study the 3D shape of a textured surface is recovered from its perspective projection image on the assumption that the texture is homogeneously distributed. To recover 3D structure, the distorting effects of the perspective projection must be distinguished from properties of the texture. In this study, paraperspective projection, approximation of perspective projection, has employed.

  • PDF

Surface Protection of YBCO Superconductors (YBCO초전도체의 표면보호에 관한연구)

  • Shan Yuqiao;Du Jinhong;Soh Daewha;Fan Zhanguo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1996.11a
    • /
    • pp.249-251
    • /
    • 1996
  • Ag coating on the textured YBCO and PTFE coating on the sintering YBCO were prepared. The critical current densities of different YBCO samples with and without coatings were compared. Both of Ag coating and PTFE coating can well protect YBCO from moisture and $CO_2$.

  • PDF

Nanoscale Pyramid Texture for High Efficiency Multi-Crystalline Silicon Solar Cells (고효율 다결정 실리콘 태양전지 제작을 위한 나노크기의 피라미드 텍스쳐 제작)

  • Heo, Jong;Park, Min-Joon;Jee, Hong sub;Kim, Jin Hyeok;Jeong, Chaehwan
    • Current Photovoltaic Research
    • /
    • v.5 no.1
    • /
    • pp.25-27
    • /
    • 2017
  • Nanoscale textured black silicon has attracted intensive attention due to its great potential as applications in multicrystalline silicon-based solar cells. It absorbs sunlight over a broad range of wavelengths but introduces large recombination centers, non-uniform doping into cell. In this study, we present a metal-assisted chemical etching technique plus alkaline etching process to fabricate nanoscale pyramid structures with optimized condition. To make the structures, silver nanoparticles-loaded mc-Si wafer was submerged into $H_2O_2/HF$ solution first for nanohole texturing the wafer and textured wafer etched again with KOH solution for making nanoscale pyramid structures. The average reflectivity (350-1050 nm) is about 8.42% with anti-reflection coating.

Study on the Efficiency of Si-cell Depending on the Texturing (표면 거칠기와 분포 상태에 따른 Si-셀 효율에 관한 연구)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
    • /
    • v.20 no.3
    • /
    • pp.189-194
    • /
    • 2011
  • Si-cell was prepared with various types owing to the etching times textured by the KOH etching solution. The pn junction for solar cell was prepared on p-type Si wafer by the furnace using the $POCl_3$ and oxygen mixed precursor, and the metalization was done using by the Al back electrode and Ag front electrode. Textured Si surface was etched by the pyramid formation. The efficiency and the fill factor was increased in the Si-cell with a large size of pyramids, because of the series resistances decrease depending on the increasing of the photon absorbance. Increasing of the absorbance occurred the induction of the short current and open voltage, and then the efficiency was increased.

Effect On Glass Texturing For Enhancement of Light Trapping in Perovskite Solar Cells

  • Kim, Dong In;Nam, Sang-Hun;Hwang, Ki-Hwan;Lee, Yong-Min;Boo, Jin-Hyo
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.387.2-387.2
    • /
    • 2016
  • Glass texturing is a sufficient method for changing the surface morphology to enhance the light trapping. In this study, glass texturing was applied to the perovskite solar cell for improving the current density. Glass substrates (back-side glass of FTO coated glass substrate) were textured by randomly structure assisted wet etching process using diluted HF solution at a constant concentration of etchants (HF:H2O=1:1). Then, the light trapping properties of suitable films were controlled over a wide range by varying the etching time (1, 2, 3, 4 and 5 min.). The surface texturing changed the reflected light in an angle that it can be reflected by substrate glass surface. As a result, Current density and cell efficiency were affected by light trapping layer using glass texturing method in perovskite solar cells.

  • PDF

Preparation of ZnO:Al transparent conductive films for solar cell (태양전지용 ZnO:Al 투명 전도막 제작)

  • Tark, Sung-Ju;Kang, Min-Gu;Kim, Dong-Hwan
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2005.11a
    • /
    • pp.568-571
    • /
    • 2005
  • Highly transparent ZnO films with low resistivity for thin film solar cell applications were fabricated at low temperature by rf magnetron sputtering. Al-doped ZnO films were deposited on glass substrates at a substrate temperature of $200^{\circ}C$. electrical and optical properties of the ZnO:Al films were investigated in terms of the reparation conditions. The transmittance of the ZnO:Al films in the visible range is 90 %. The lowest resistivity of the ZnO:Al films is about $5.7\times10^{-4}$ $\Omega$ cm at the Al content of 2.5 wt% with the film thickness of 500 nm. After deposition, the smooth surface of ZnO:Al films were etched in diluted HCl (0.5%) to investigate the variation of electrical and surface morphology properties due to an textured surface.

  • PDF

Lubrication Characteristics of Laser Textured Parallel Thrust Bearing : Part 2 - Effect of Dimple Location (Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제2보 - 딤플 위치의 영향)

  • Park, Tae-Jo;Hwang, Yun-Geon
    • Tribology and Lubricants
    • /
    • v.26 no.1
    • /
    • pp.1-6
    • /
    • 2010
  • In the last decade, laser surface texturing (LST) has emerged as a viable option of surface engineering. Many problems related with mechanical components such as thrust bearings, mechanical face seals and piston rings, etc, LST result in significant improvement in load capacity, wear resistance and reduction in friction force. It is mainly experimentally reported the micro-dimpled bearing surfaces can reduce friction force, however, precise theoretical results are not presented until now. In this paper, a commercial computational fluid dynamics(CFD) code, FLUENT is used to investigate the lubrication characteristics of a parallel thrust bearing having 3-dimensional micro-dimple. The results show that the pressure, velocity and density distributions are highly affected by the location and number of dimple. The numerical method and results can be use in design of optimum dimple characteristics, and further researches are required.

Symmetry and depth-dependent orders of subsurface defects in Mn-doped Sb(111) studied by using STM

  • Cho, Doo-Hee;Kim, Min-Seong;Lyo, In-Whan
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.57-57
    • /
    • 2010
  • Sb(111) is a spin textured surface due to the strong spin-orbit coupling, often viewed as a proto-type topological insulator. We used scanning tunneling microscopy (STM) to characterize various Mn-induced subsurface defects existing at the surface of Mn-doped Sb at 50 K. Our STM images show that every defect exhibits 3-fold symmetry with a single rotational orientation and can be categorized by their shapes and sizes. We found more than 10 types of subsurface defects with distinctive orders, which allows the resolution of the vertical positions of the magnetic dopants lying more than 10 layers down from the surface. We will discuss about our findings in comparison with theoretical results.

  • PDF