Investigations on the Influence of Surface Textures on Optical Reflectance of Multi-crystalline Silicone (MC-Si) Crystal Surfaces-Simulations and Experiments

2021 ◽  
Vol 11 (2) ◽  
pp. 375-383
Author(s):  
Sudeep Ullattil ◽  
Sudheesh Kakkarath ◽  
Vinod Viswambharanunnithan ◽  
Suresh Padiyath Ramannair
Keyword(s):  
Surface Topography ◽  
Incident Light ◽  
Wave Length ◽  
Solar Spectrum ◽  
Wafer Surface ◽  
Solar Pv ◽  
Crystal Surfaces ◽  
Optical Reflectance ◽  
Surface Textures ◽  
Major Loss

MC-Si is the most widely used material for making solar PV cells. In spite of the considerable research on improving the conversion efficiency of MC-Si solar PV cells still it remains well within the range of 15-20%. Optical reflectance being the major loss of incident solar energy, efforts are being made to reduce the optical reflectance of solar cell surfaces. Among the several methods proposed, creation of well-defined surface topography on the cell surface remains a promising option. Micro/nano level features with various dimensions and distributions have been created on MC-Si crystal surfaces using a femto-second pulsed laser and the influence of surface topography on optical reflectance in the incident light wave length of 350 – 1000 nm have been studied and compared with the simulation results obtained using OPAL2 software. Experimental results indicate that surface textures on the wafer surface lead to the reduction of optical reflectance in the range of 20-35% in comparison with plain surface. Width of micro grooves have less significant effect on the optical reflectance in comparison with pitch between the micro grooves. Best reduction in reflectance is exhibited by the texture having a groove width of 30 mm and a pitch of 100 mm. A post texturing etching operation is found to have detrimental effect on the ability of micro/nano level features in decreasing the optical reflectance in the preferred wavelength of solar spectrum due to the flattening of nano level features created within the micro grooves due to laser texturing.

Design and Evaluation of the Fresnel-Lens Based Solar Concentrator System Through a Statistical-Algorithmic Approach

2018 ◽  
Author(s):  
Hassan Qandil ◽  
Weihuan Zhao
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Incident Light ◽  
Thermal Analyses ◽  
Solar Spectrum ◽  
Chromatic Aberration ◽  
Fresnel Lens ◽  
Optimum Number ◽  
Solar Concentrator ◽  
Receiver System

A novel non-imaging Fresnel-lens-based solar concentrator-receiver system has been investigated to achieve high-efficiency photon and heat outputs with minimized effect of chromatic aberrations. Two types of non-imaging Fresnel lenses, a spot-flat lens and a dome-shaped lens, are designed through a statistical algorithm incorporated in MATLAB. The algorithm optimizes the lens design via a statistical ray-tracing methodology of the incident light, considering the chromatic aberration of solar spectrum, the lens-receiver spacing and aperture sizes, and the optimum number of prism grooves. An equal-groove-width of the Poly-methyl-methacrylate (PMMA) prisms is adopted in the model. The main target is to maximize ray intensity on the receiver’s aperture, and therefore, achieve the highest possible heat flux and output concentration temperature. The algorithm outputs prism and system geometries of the Fresnel-lens concentrator. The lenses coupled with solar receivers are simulated by COMSOL Multiphysics. It combines both optical and thermal analyses for the lens and receiver to study the optimum lens structure for high solar flux output. The optimized solar concentrator-receiver system can be applied to various devices which require high temperature inputs, such as concentrated photovoltaics (CPV), high-temperature stirling engine, etc.

scholarly journals Solar eclipse of 1900, May 28.—General discussion of spectroscopic results

1903 ◽  
Vol 71 (467-476) ◽  
pp. 228-229
Keyword(s):  
Solar Eclipse ◽  
Wave Length ◽  
Solar Spectrum ◽  
Great Majority ◽  
Dark Line ◽  
Bright Line ◽  
Flash Spectrum

In a general way the conclusions arrived at from the discussion of the spectra obtained in 1898 are amply confirmed and extended by the present results. It is now shown that every strong dark line of the solar spectrum exceeding Rowland’s intensity 7 is found in these spectra as a bright line; and the great majority of the bright lines of the flash spectrum, excluding hydrogen and helium lines, coincide with dark lines of intensity not less than 3. Most of the bright arcs of the flash spectrum are well-defined narrow lines admitting of considerable accuracy in the measures, and the present determinations of wave-length indicate that the coinci­dence of the bright lines with the dark lines is exact within ·05 t. m. for all the well-defined lines.

scholarly journals VI. Corrections to the computed lengths of waves of light published in the Philosophical Transactions of the year 1868

1872 ◽  
Vol 162 ◽  
pp. 89-109
Keyword(s):  
Spectral Line ◽  
Royal Society ◽  
Wave Length ◽  
Solar Spectrum ◽  
Spectral Lines ◽  
Fifth Order ◽  
Principal Lines ◽  
General Table

In a paper communicated to the Royal Society in the year 1867, and printed in the Philosophical Transactions for 1868, I attempted the computation of the Lengths of Waves of Light for all the lines which Kirchhoff had observed in the Solar Spectrum, by adopting an algebraical formula of the fifth order, and substituting in it for every spectral line the value of Kirchhoff’s measure for that line, the numerical bases of the formula being derived from Fraunhofer’s and Ditscheiner’s measures of the wave-lengths for six principal lines. Subsequently I obtained the means of comparing many of my computed results with measures of wave-lengths by Ångstrȍm and Ditscheiner, and l found that the discordances were far larger than I had anticipated. I remarked, however, “By means of the comparison........ there is no difficulty in computing for any other line the correction that ought to be applied to the wave-length in the principal Tables, in order to exhibit the true wave-lengths on Ditscheiner’s scale, without appreciable error.” Want of leisure long prevented me from entering upon the examination necessary for preparing, in a form easy for applications, the correction which my numbers required. Lately, however, I have taken it up; and I have constructed a Table of corrections to the numbers of my Table generally, and I have applied them, both to the general Table of wave-lengths and to the values of wave-lengths for the spectral lines of the atmosphere and several metals (the accurate exhibition of which was, in fact, the first object of my computations). I now offer these corrections and corrected numbers for the acceptance of the Royal Society.

scholarly journals Numerical Study of Multilayer Planar Film Structures for Ideal Absorption in the Entire Solar Spectrum

2020 ◽  
Vol 10 (9) ◽  
pp. 3276 ◽  
Author(s):  
Wei Chen ◽  
Jing Liu ◽  
Wen-Zhuang Ma ◽  
Gao-Xiang Yu ◽  
Jing-Qian Chen ◽  
...  
Keyword(s):  
Noble Metals ◽  
Numerical Study ◽  
Incident Light ◽  
Solar Spectrum ◽  
Fdtd Simulation ◽  
Polarization Angle ◽  
Solar Absorber ◽  
Solar Energy Harvesting ◽  
Planar Film ◽  
Planar Films

Here, we have theoretically proposed an ideal structure of selective solar absorber with multilayer planar films, which can absorb the incident light throughout the entire solar spectrum (300–2500 nm) and over a wide angular range, whatever the polarization angle of 0°~90°. The efficiency of the proposed absorber is proven by the Finite-Difference Time Domain (FDTD) simulation. The average absorption rate over the solar spectrum is up to 96.6%. The planar design is extremely easy to fabricate and modify, and this structure does not require lithographic processes to finish the absorbers. Improvements of the solar absorber on the basis of planar multilayer-film structures is attributed to multiple asymmetric highly lossy Fabry–Perot resonators. Because of having many virtues, such as using different refractory and non-noble metals, having angle and polarization independence, and having ideal absorption for entire solar spectrum, our proposed absorbers are promising candidates for practical industrial production of the solar-energy harvesting.

scholarly journals The molecular scattering of light in vapours and in liquids and its relation to the opalescence observed in the critical state

1922 ◽  
Vol 102 (715) ◽  
pp. 151-161 ◽  
Keyword(s):  
Critical Point ◽  
Critical State ◽  
Incident Light ◽  
Wave Length ◽  
Molecular Scattering ◽  
Avogadro’S Number ◽  
Quantitative Manner ◽  
The Mean ◽  
Good Agreement ◽  
Molecular Scattering Of Light

It has long been known that in the immediate vicinity of the critical state, many substances exhibit a strong and characteristic opalescence. In recent years, the phenomenon has been studied by Travers and Usher in the case of carefully purified CS 2 , SO 2 , and ether, by S. Young, by F. B. Young in the case of ether, and in a quantitative manner by Kammerlingh Onnes and Keesom in the case of ethylene. An explanation of the phenomenon on thermodynamic principles as due to the accidental deviations of density arising in the substance was put forward by Smoluchowski. He obtained an expression for the mean fluctuation of density in terms of the compressibility of the substance, and later, Einstein applied Maxwell’s equations of the electromagnetic field to obtain an expression for the intensity of the light scattered in consequence of such deviations of density. He showed that the fraction α of the incident energy scattered in the substance per unit volume is 8 π 3 /27 RT β ( μ 2 – 1) 2 ( μ 2 + 2) 2 /N λ 4 (1) In this, R and N are the gas constant and Avogadro’s number per grammolecule, β is the isothermal compressibility of the substance, μ is the refractive index and λ is the wave-length of the incident light. Keesom tested this formula over a range of 2·35° above the critical point of ethylene and found good agreement except very close to the critical point.

Flat Crystal X-Ray Optics

1957 ◽  
Vol 1 ◽  
pp. 193-206 ◽  
Author(s):  
William J. Campbell ◽  
Melvin Leon ◽  
John Thatcher
Keyword(s):  
Wave Length ◽  
Pulse Height ◽  
Line Profiles ◽  
Line Broadening ◽  
Crystal Surfaces ◽  
X Ray ◽  
Line Intensities ◽  
Long Wave ◽  
On Line ◽  
College Park

AbstractAn investigation was undertaken by the Bureau of Mines at College Park, Md., to determine the effect of various combinations of collimators, analyzing crystals and detectors on line intensities, line-to-backgrouhd ratios, and spectral resolution. The research showed that line broadening due to mosaic crystal surfaces was greatly reduced and line splitting from faults was eliminatedby the use of two fine collimators (0.005 inch, spacing, 4 inch length). Line intensities were reduced, but lineto- background ratios arid line profiles were substantially improved with double collimators. Pulse height discrimination resulted in marked improvement in the line-to-background ratio in the long-wave length region, 2 to 10 A, but was much less effective for shorter wave lengths.

scholarly journals Influence of the Drive Plate with Different Surface Textures on the Property of Carbonyl Iron-Based Magnetorheological Fluid

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
He Lu ◽  
Lifeng Wang ◽  
Lili Dai ◽  
Hongxing Ding ◽  
Qiuxiang Zhang ◽  
...  
Keyword(s):  
Surface Topography ◽  
Carbonyl Iron ◽  
Magnetorheological Fluid ◽  
Test Methods ◽  
Wear Property ◽  
Test Bed ◽  
Surface Textures ◽  
Surface Topographies ◽  
Iron Based ◽  
Scanning Electron

Aiming to study the effect of drive plate with different surface topographies on the wear property of magnetorheological fluid (MRF), some specific experiments are carried out and analyzed in this paper. Firstly, experiment materials and test methods for MRF are elaborated, and four different surface topography drive plates are designed and manufactured. MRF test-bed is built up to test the rheological properties of MRF. Moreover, the surface morphology of particles is taken using a scanning electron microscope (SEM). Finally, experimental results show that there are remarkable influences on tribological properties of carbonyl iron-based MRF with different drive plates. Therefore, the drive plate with specific surface topography can meet the needs of different MRF transmission systems.

scholarly journals Localized Surface Plasmons Enhanced Light Transmission into c-Silicon Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Y. Premkumar Singh ◽  
Amit Jain ◽  
Avinashi Kapoor
Keyword(s):  
Solar Cells ◽  
Metallic Nanoparticles ◽  
Large Scale ◽  
Light Transmission ◽  
Low Cost ◽  
Incident Light ◽  
Solar Spectrum ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Al Nanoparticles

The paper investigates the light incoupling into c-Si solar cells due to the excitation of localized surface plasmon resonances in periodic metallic nanoparticles by finite-difference time-domain (FDTD) technique. A significant enhancement of AM1.5G solar radiation transmission has been demonstrated by depositing nanoparticles of various metals on the upper surface of a semi-infinite Si substrate. Plasmonic nanostructures located close to the cell surface can scatter incident light efficiently into the cell. Al nanoparticles were found to be superior to Ag, Cu, and Au nanoparticles due to the improved transmission of light over almost the entire solar spectrum and, thus, can be a potential low-cost plasmonic metal for large-scale implementation of solar cells.

Light of Very Short Wave-Length (2100 A.) in the Solar Spectrum

Nature ◽  
1934 ◽  
Vol 134 (3388) ◽  
pp. 535-535 ◽  
Author(s):  
EDGAR MEYER ◽  
M. SCHEIN ◽  
B. STOLL
Keyword(s):  
Wave Length ◽  
Solar Spectrum ◽  
Short Wave ◽  
Short Wave Length

scholarly journals I. On the new gas obtained from uraninite. Fourth note

1895 ◽  
Vol 58 (347-352) ◽  
pp. 192-192
Keyword(s):  
Wave Length ◽  
Solar Spectrum ◽  
First Order ◽  
Infra Red ◽  
Chromospheric Line

Continued experiments on the gases obtained by heating the minerals bröggerite and euxenite in vacuo have revealed the presence in the spectrum of an important line in the infra-red. By comparisons with the solar spectrum in the first order grating spectrum, the wavelength of the line has been approximately determined as 7065. There can be little doubt, from the observations which have been made, that this new line is coincident with a chromospheric line which occurs in Young’s list, having a frequency of 100, of which the wave-length on, Row land’s scale is stated to be 7065·5.

Sign in / Sign up

Export Citation Format

Share Document