Silicon based core-shell silicon nanowires for broadband and wide angle antireflection

2013 ◽  
Vol 1510 ◽  
Author(s):  
P. Pignalosa ◽  
H. Lee ◽  
W. Guo ◽  
X. Duan ◽  
Y. Yi
Keyword(s):  
Silicon Nanowires ◽  
Solar Spectrum ◽  
Normal Incidence ◽  
Index Structure ◽  
Core Shell ◽  
Wide Angle ◽  
Si Nanowires ◽  
Graded Index ◽  
Wide Range ◽  
Silicon Based

ABSTRACTAntireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm) and wide angle (from normal incidence to 60°) antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si) nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.

scholarly journals Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection

AIP Advances ◽  
2011 ◽  
Vol 1 (3) ◽  
pp. 032124 ◽  
Author(s):  
P. Pignalosa ◽  
H. Lee ◽  
L. Qiao ◽  
M. Tseng ◽  
Y. Yi
Keyword(s):  
Silicon Nanowires ◽  
Core Shell ◽  
Wide Angle ◽  
Graded Index

SYNTHESIS AND PROPERTY OF MULTIFUNCTIONAL Fe3O4@SiO2@CeO2@Au COMPOSITE MICROSPHERES

NANO ◽  
2012 ◽  
Vol 07 (06) ◽  
pp. 1250042 ◽  
Author(s):  
YANG WANG ◽  
HAORAN SUN ◽  
TONG ZHANG ◽  
YUHUA SHEN ◽  
JIAN ZHANG ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Coating Layer ◽  
Solar Spectrum ◽  
Core Shell ◽  
Composite Microspheres ◽  
Wide Range ◽  
Spectrum Response

In this paper, Fe3O4@SiO2@CeO2@Au core/shell microspheres were synthesized through hydrolysis and solvothermal processes. The results indicated that the magnetic Fe3O4 cores were well wrapped by the coating layer of SiO2/CeO2 with a thickness of 50 nm, and Au nanoparticles with 35 nm in diameter were attached on the shell. The microspheres showed a monodispersity and superparamagnetism. The composites showed excellent ability to absorb a wide range of wavelengths including visible and NIR region (from 250 nm to 800 nm), making it a potential full solar spectrum response photocatalyst for sunlight applications.

Studies of Silicon Nanowires with Different Parameters — By PECVD

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660010
Author(s):  
S. Leela ◽  
T. Abirami ◽  
Sekhar Bhattacharya ◽  
Nafis Ahmed ◽  
S. Monika ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Growth Parameters ◽  
Gold Catalyst ◽  
Chemical Vapor ◽  
Spectral Studies ◽  
Si Nanowires ◽  
Wide Range ◽  
Different Temperatures ◽  
Carrier Gases ◽  
Growth Controls

One-dimensional nanostructures such as nanowires have a wide range of applications. Silicon is the best competitive material for the carbon nanotubes (CNTs). Carbon and silicon have some similar and peculiar properties. Silicon nanowires (SiNWs) were synthesized using plasma enhanced chemical vapor deposition (PECVD) on p-Si (111) wafer. Gold is used as a catalyst for the growth of the SiNWs. Based on our fundamental understanding of vapor–liquid–solid (VLS) nanowire growth mechanism, different levels of growth controls have been achieved. Gold catalyst deposited and annealed at different temperatures with different thicknesses (450[Formula: see text]C, 500[Formula: see text]C and 550[Formula: see text]C, 600[Formula: see text]C, 650[Formula: see text]C for 4[Formula: see text]min and 8[Formula: see text]min and 3[Formula: see text]nm, 5[Formula: see text]nm, 30[Formula: see text]nm Au thickness). SiNW grown by PECVD with different carrier gases varies with flow rate. We observed the different dimensions of Si nanowires by FESEM and optimized the growth parameters to get the vertical aligned and singular Si nanowires. Optical phonon of the Si nanowires and crystallinity nature were identified by Raman spectral studies.

Bias Dependence of Sub-Bandgap Light Detection for Core–Shell Silicon Nanowires

Nano Letters ◽  
2012 ◽  
Vol 12 (11) ◽  
pp. 5929-5935 ◽  
Author(s):  
Yuchun Zhou ◽  
Yu-hsin Liu ◽  
James Cheng ◽  
Yu-Hwa Lo
Keyword(s):  
Silicon Nanowires ◽  
Core Shell ◽  
Light Detection

scholarly journals Synthesis and Advanced Characterization of Polymer-Protein Core-Shell Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 730
Author(s):  
Erik Sarnello ◽  
Tao Li
Keyword(s):  
Particle Size ◽  
Small Angle ◽  
Core Shell ◽  
Assembly Process ◽  
Shell Nanoparticles ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Core Shell Nanoparticles ◽  
Ray Scattering

Enzyme immobilization techniques are widely researched due to their wide range of applications. Polymer–protein core–shell nanoparticles (CSNPs) have emerged as a promising technique for enzyme/protein immobilization via a self-assembly process. Based on the desired application, different sizes and distribution of the polymer–protein CSNPs may be required. This work systematically studies the assembly process of poly(4-vinyl pyridine) and bovine serum albumin CSNPs. Average particle size was controlled by varying the concentrations of each reagent. Particle size and size distributions were monitored by dynamic light scattering, ultra-small-angle X-ray scattering, small-angle X-ray scattering and transmission electron microscopy. Results showed a wide range of CSNPs could be assembled ranging from an average radius as small as 52.3 nm, to particles above 1 µm by adjusting reagent concentrations. In situ X-ray scattering techniques monitored particle assembly as a function of time showing the initial particle growth followed by a decrease in particle size as they reach equilibrium. The results outline a general strategy that can be applied to other CSNP systems to better control particle size and distribution for various applications.

scholarly journals Comparing optical performance of a wide range of perovskite/silicon tandem architectures under real-world conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Manvika Singh ◽  
Rudi Santbergen ◽  
Indra Syifai ◽  
Arthur Weeber ◽  
Miro Zeman ◽  
...  
Keyword(s):  
Solar Cells ◽  
Real World ◽  
Solar Spectrum ◽  
Photocurrent Density ◽  
Angle Of Incidence ◽  
Optical Study ◽  
Optical Performance ◽  
Tandem Solar Cells ◽  
Bottom Cell ◽  
Wide Range

Abstract Since single junction c-Si solar cells are reaching their practical efficiency limit. Perovskite/c-Si tandem solar cells hold the promise of achieving greater than 30% efficiencies. In this regard, optical simulations can deliver guidelines for reducing the parasitic absorption losses and increasing the photocurrent density of the tandem solar cells. In this work, an optical study of 2, 3 and 4 terminal perovskite/c-Si tandem solar cells with c-Si solar bottom cells passivated by high thermal-budget poly-Si, poly-SiOx and poly-SiCx is performed to evaluate their optical performance with respect to the conventional tandem solar cells employing silicon heterojunction bottom cells. The parasitic absorption in these carrier selective passivating contacts has been quantified. It is shown that they enable greater than 20 mA/cm2 matched implied photocurrent density in un-encapsulated 2T tandem architecture along with being compatible with high temperature production processes. For studying the performance of such tandem devices in real-world irradiance conditions and for different locations of the world, the effect of solar spectrum and angle of incidence on their optical performance is studied. Passing from mono-facial to bi-facial tandem solar cells, the photocurrent density in the bottom cell can be increased, requiring again optical optimization. Here, we analyse the effect of albedo, perovskite thickness and band gap as well as geographical location on the optical performance of these bi-facial perovskite/c-Si tandem solar cells. Our optical study shows that bi-facial 2T tandems, that also convert light incident from the rear, require radically thicker perovskite layers to match the additional current from the c-Si bottom cell. For typical perovskite bandgap and albedo values, even doubling the perovskite thickness is not sufficient. In this respect, lower bandgap perovskites are very interesting for application not only in bi-facial 2T tandems but also in related 3T and 4T tandems.

CdSe/CdS Quantum Dot Core-Shell for Silicon Solar Cell Efficiency Enhancement

2020 ◽  
Vol 29 ◽  
pp. 8-14
Author(s):  
Manal Midhat Abdullah ◽  
Omar Adnan Ibrahim
Keyword(s):  
Solar Cell ◽  
Silicon Solar Cell ◽  
Energy Gap ◽  
Spectral Response ◽  
Solar Spectrum ◽  
Core Shell ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Electron Hole Pair ◽  
Pair Generation

Core-shell nanocrystals are utilized to improve vitality conversion efficiency of Si based solar cells. In the present work, a study of synthesis and characterization of photo luminescent, down-shifting, core-shell CdSe/CdS quantum dots is introduced. The QD,s absorb in the UV range (350nm) of the solar spectrum and emit photons with wavelengths centered at (574 nm). Calculated energy gap is (2.16 eV), which is well suited for Silicon absorption and electron-hole pair generation. The grain size is ranged between (1.814 and 3.456 nm). Results show that the cell efficiency is improved from (8.81%) (For a reference silicon solar cell) to (10.07%) (For a CdSe/CdS QD deposited directly on the surface of the solar cell). This improvement is referred to the spreading of the absorbed solar radiation over the spectral response of the Si solar cell.

Size-Dependent Elasticity of Silicon Nanowires

2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
First Principles ◽  
Si Nanowires ◽  
Size Dependent ◽  
Reconstructed Surfaces ◽  
Strain Relationship ◽  
Dynamics Simulations ◽  
Good Agreement

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.

Polymer-assisted synthesis of aligned amorphous silicon nanowires and their core/shell structures with Au nanoparticles

2004 ◽  
Vol 397 (1-3) ◽  
pp. 128-132 ◽  
Author(s):  
Xing-bin Yan ◽  
Tao Xu ◽  
Shan Xu ◽  
Gang Chen ◽  
Qun-ji Xue ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Silicon Nanowires ◽  
Au Nanoparticles ◽  
Shell Structures ◽  
Core Shell

Micropattern Effect on Breast Cancer Cells Behavior on Isotropically Etched Silicon Microenvironments

2010 ◽  
Author(s):  
Mehdi Nikkhah ◽  
Jeannine S. Strobl ◽  
Bhanu Peddi ◽  
Adedamola Omotosho ◽  
Masoud Agah
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Three Dimensional ◽  
Cancer Diagnostics ◽  
Breast Cancer Diagnostics ◽  
Wide Range ◽  
Etched Silicon ◽  
Directed Motility ◽  
Etched Surface ◽  
Silicon Based

In this paper we are investigating three dimensional (3-D) silicon-based microenvironments as potential platforms for breast cancer diagnostics. We have developed isotropically etched microstructures with a wide range of geometrical patterns for this purpose. Our results indicate that with the etched surface ratio of ∼65%, it is possible to capture 80–90% of the cancer cells within each silicon chip. After treatment of the cells with mitomycin C (to block the cell growth) more number of the cells are trapped inside the etched features for longer cultures times (72 h) suggesting that there is a directed motility and attraction of the cells toward the etched cavities and by optimally designing the etched features, the proposed platforms can be potentially used for diagnostics purposes.

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