scholarly journals Improving Absorption in Single Silicon Nanowires by Symmetry-breaking Design from Square to Rectangular Cross-section

2021 ◽  
Author(s):  
Wenfu Liu
Keyword(s):  
Symmetry Breaking ◽  
Silicon Nanowires ◽  
Light Absorption ◽  
High Efficiency ◽  
Rectangular Cross Section ◽  
Photovoltaic Devices ◽  
Vertical Side ◽  
Photovoltaic Applications ◽  
Single Nanowires ◽  
Horizontal Side

Light absorption in single nanowires (NWs) is one of the most crucial factors for photovoltaic applications. In this paper, we carried out a detailed investigation of light absorption in single rectangular NWs (RNWs). We show that the RNWs exhibit improved light absorption compared with the square NWs (SNWs), which can be attributed to the symmetry-breaking structure that can increase the light path length by increasing the vertical side and the enhanced leaky mode resonances (LMRs) by decreasing the horizontal side. We found that the light absorption in silicon RNWs can be enhanced by engineering the horizontal and vertical sides, the photocurrent is significantly increased by 276.5% or 82.9% compared with that of the SNWs with the same side length as the horizontal side of 100 nm or the vertical side of 1000 nm, respectively. This work provides an effective way for designing high-efficiency single NW photovoltaic devices based on the symmetry breaking from the SNWs to RNWs.

scholarly journals Light Management in Single Rectangular Silicon Nanowires for Photovoltaic Applications

2020 ◽  
Author(s):  
Wenfu Liu
Keyword(s):  
Cross Section ◽  
Silicon Nanowires ◽  
High Efficiency ◽  
Light Harvesting ◽  
Rectangular Cross Section ◽  
Light Illumination ◽  
Vertical Side ◽  
Photovoltaic Applications ◽  
Light Management ◽  
Horizontal Side

Light management in single nanowires (NWs) is of great importance for photovoltaic applications. However, square NWs (SNWs) can limit their light-trapping ability due to high geometrical symmetry. In this work, we present a detailed study of light management in single silicon NWs with a rectangular cross-section (RNWs). We demonstrate that the RNWs exhibit significantly enhanced light-harvesting compared with the SNWs, which can be attributed to the symmetry-broken structure that can orthogonalize the direction of light illumination and the leaky mode resonances (LMRs). That is, the rectangular cross-section can simultaneously increase the light path length by increasing the vertical side and reshape the LMR modes by decreasing the horizontal side. We found that the light absorption can be engineered via tuning the horizontal and vertical sides, the photocurrent is significantly enhanced by 276.5% or 82.9% in comparison with that of the SNWs with the same side length as the horizontal side of 100 nm or the vertical side of 1000 nm, respectively. This work advances our understanding of how to improve light-harvesting based on the symmetry breaking from the SNWs to RNWs and provides an effective way for designing high-efficiency single NW photovoltaic devices.

scholarly journals Enhanced Light-Harvesting in Single Rectangular Silicon Nanowires

2021 ◽  
Vol 16 (3) ◽  
pp. 428-433
Author(s):  
Wenfu Liu ◽  
Xin Lio ◽  
Yinling Wang ◽  
Bin Wen
Keyword(s):  
Solar Cells ◽  
Silicon Nanowires ◽  
Light Harvesting ◽  
Numerical Results ◽  
Leaky Mode ◽  
Light Path ◽  
Vertical Side ◽  
Single Nanowires ◽  
Horizontal Side

Light-harvesting of single nanowires is very crucial to enhance conversion efficency of solar cells. Here, we systematically examined light-harvesting of single rectangular nanowires and found that light-harvesting of rectangular nanowires is increased contrasted with that of square nanowires, which is because decreasing the horizontal side can strengthen the leaky mode resonances and increasing the vertical side can increase the length of the light path. Numerical results showed that the photocurrent of single rectangular silicon nanowires is dramatically enhanced by 82.9% or 276.5% in comparison with that of square nanowires with the same vertical side (1000 nm) or horizontal side (100 nm), respectively. This work indicates that light-harvesting of single nanowires can be improved by decreasing the symmetry from the square to rectangular nanowires.

scholarly journals Light Trapping in Single Elliptical Nanowires

2020 ◽  
Author(s):  
Wenfu Liu ◽  
Yinling Wang ◽  
Xiaolei Guo ◽  
Jun Song ◽  
Xiao Wang ◽  
...  
Keyword(s):  
Cross Section ◽  
High Efficiency ◽  
Light Trapping ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Elliptical Cross Section ◽  
Light Illumination ◽  
Elliptical Cross ◽  
Photovoltaic Applications ◽  
Single Nanowires

Light trapping in single nanowires (NWs) are of vital importance for photovoltaic applications. However, circular NWs (CNWs) can limit its light-trapping ability due to high geometrical symmetry. In this work, we present a detailed study of light trapping in single NWs with an elliptical cross-section (ENWs). We demonstrate that the ENWs exhibit significantly enhanced light trapping compared with the CNWs, which can be ascribed to the symmetry-broken structure that can orthogonalize the direction of light illumination and the leaky mode resonances (LMRs). That is, the elliptical cross-section can simultaneously increase the light path length by increasing the vertical axis and reshape the LMR modes by decreasing the horizontal axis. We found that the light absorption can be engineered via tuning the horizontal and vertical axes, the photocurrent is significantly enhanced by 374.0% (150.3%, 74.1%) or 146.1% (61.0%, 35.3%) in comparison with that of the CNWs with the same diameter as the horizontal axis of 100 (200, 400) nm or the vertical axis of 1000 nm, respectively. This work advances our understanding of how to improve light trapping based on the symmetry breaking from the CNWs to ENWs and provides a rational way for designing high-efficiency single or self-assembled NW photovoltaic devices.

scholarly journals Off-Resonant Absorption Enhancement in Single Nanowires via Graded Dual-Shell Design

2020 ◽  
Author(s):  
Wenfu Liu ◽  
Xiaolei Guo ◽  
Shule Xing ◽  
Haizi Yao ◽  
Yinling Wang ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Efficiency ◽  
Light Trapping ◽  
Resonant Absorption ◽  
Photocurrent Density ◽  
Absorption Enhancement ◽  
Photovoltaic Devices ◽  
Graded Index ◽  
Single Nanowires ◽  
Absorption Mode

Single nanowires (NWs) are of great importance for various optoelectronic applications, especially solar cells serving as powering nanoscale devices. However, weak off-resonant absorption can limit its light-harvesting capability. Here, we propose a single NW coated with the graded-index dual shells (DSNW). We demonstrate that with the proper thickness and refractive index of the inner shell, the DSNW exhibits significantly enhanced light trapping compared with the bare NW (BNW), and the NW only coated with the outer shell (OSNW) and inner shell (ISNW), which can be attributed to the optimal off-resonant absorption mode profiles due to the improved coupling between the reemitted light of the leak mode resonances of the Si core and the nanofocusing light from the dual shells with the graded refractive index. We found that the light absorption can be adjusted via tuning the thickness and refractive index of the inner shell, the photocurrent density is significantly enhanced by 134% (56%, 12%) in comparison with that of the BNW (OSNW, ISNW). This work advances our understanding of how to improve off-resonant absorption by applying graded dual shells and provides a new choice for designing high-efficiency single NW photovoltaic devices.

scholarly journals Light Trapping in Single Elliptical Silicon Nanowires

2020 ◽  
Author(s):  
Wenfu Liu ◽  
Yinling Wang ◽  
Xiaolei Guo ◽  
Jun Song ◽  
Xiao Wang ◽  
...  
Keyword(s):  
Cross Section ◽  
Silicon Nanowires ◽  
High Efficiency ◽  
Light Trapping ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Elliptical Cross Section ◽  
Light Illumination ◽  
Elliptical Cross ◽  
Single Nanowires

Light trapping in single nanowires (NWs) are of vital importance for photovoltaic applications. However, circular NWs (CNWs) can limit its light-trapping ability due to high geometrical symmetry. In this work, we present a detailed study of light trapping in single NWs with an elliptical cross-section (ENWs). We demonstrate that the ENWs exhibit significantly enhanced light trapping compared with the CNWs, which can be ascribed to the symmetry-broken structure that can orthogonalize the direction of light illumination and the leaky mode resonances (LMRs). That is, the elliptical cross-section can simultaneously increase the light path length by increasing the vertical axis and reshape the LMR modes by decreasing the horizontal axis. We found that the light absorption can be engineered via tuning the horizontal and vertical axes, the photocurrent is significantly enhanced by 374.0% (150.3%, 74.1%) or 146.1% (61.0%, 35.3%) in comparison with that of the CNWs with the same diameter as the horizontal axis of 100 (200, 400) nm or the vertical axis of 1000 nm, respectively. This work advances our understanding of how to improve light trapping based on the symmetry breaking from the CNWs to ENWs and provides a rational way for designing high-efficiency single or self-assembled NW photovoltaic devices.

scholarly journals Light Trapping in Single Elliptical Silicon Nanowires

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2121
Author(s):  
Wenfu Liu ◽  
Yinling Wang ◽  
Xiaolei Guo ◽  
Jun Song ◽  
Xiao Wang ◽  
...  
Keyword(s):  
Cross Section ◽  
Silicon Nanowires ◽  
High Efficiency ◽  
Light Trapping ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Elliptical Cross Section ◽  
Light Illumination ◽  
Elliptical Cross ◽  
Single Nanowires

Light trapping in single nanowires (NWs) is of vital importance for photovoltaic applications. However, circular NWs (CNWs) can limit their light-trapping ability due to high geometrical symmetry. In this work, we present a detailed study of light trapping in single silicon NWs with an elliptical cross-section (ENWs). We demonstrate that the ENWs exhibit significantly enhanced light trapping compared with the CNWs, which can be ascribed to the symmetry-broken structure that can orthogonalize the direction of light illumination and the leaky mode resonances (LMRs). That is, the elliptical cross-section can simultaneously increase the light path length by increasing the vertical axis and reshape the LMR modes by decreasing the horizontal axis. We found that the light absorption can be engineered via tuning the horizontal and vertical axes, the photocurrent is significantly enhanced by 374.0% (150.3%, 74.1%) or 146.1% (61.0%, 35.3%) in comparison with that of the CNWs with the same diameter as the horizontal axis of 100 (200, 400) nm or the vertical axis of 1000 nm, respectively. This work advances our understanding of how to improve light trapping based on the symmetry breaking from the CNWs to ENWs and provides a rational way for designing high-efficiency single NW photovoltaic devices.

HIGH EFFICIENCY, LARGE-AREA PHOTOVOLTAIC DEVICES USING AMORPHOUS Si : F : H ALLOY

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-463-C4-466
Author(s):  
A. Madan ◽  
W. Czubatyj ◽  
J. Yang ◽  
J. McGill ◽  
S. R. Ovshinsky
Keyword(s):  
High Efficiency ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Amorphous Si

Enhanced Absorption of Single Silicon Nanowire with Si3N4 Shell for Photovoltaic Applications

2015 ◽  
Vol 1090 ◽  
pp. 173-177 ◽  
Author(s):  
Wen Fu Liu ◽  
Hua Li Hao
Keyword(s):  
Light Scattering ◽  
Light Absorption ◽  
Calculated Result ◽  
Scattering Theory ◽  
Enhancement Factor ◽  
Shell Thickness ◽  
Silicon Nanowire ◽  
Enhanced Absorption ◽  
Photovoltaic Applications

Based on the Lorenz-Mie light scattering theory, we have calculated the light absorption of single silicon nanowire with Si3N4coating, and compared with pure single silicon nanowire. The calculated result indicates that there exists an enhanced absorption in the Si3N4-coated silicon nanowire and shows a great photocurrent enhancement factor (~70%) for the coaxial NW with the shell thickness of ~70 nm. For a special shell thickness (175 nm) in the Si3N4-coated silicon nanowire forr= 150 nm, the enhancement comes up to ~98.45%.

Electrophoretic Deposition of CdSe Nanocrystals for Photovoltaic Applications

2007 ◽  
Vol 1031 ◽  
Author(s):  
Nathanael Smith ◽  
Kevin J Emmett ◽  
Sandra J Rosenthal
Keyword(s):  
Titanium Dioxide ◽  
Electrophoretic Deposition ◽  
Room Temperature ◽  
Tio2 Thin Film ◽  
Cdse Nanocrystals ◽  
Photovoltaic Devices ◽  
Photovoltaic Applications ◽  
Nanocrystalline Titanium ◽  
Alternative Techniques

AbstractCdSe nanocrystals chemically linked to nanocrystalline titanium dioxide substrates form a promising material for nanostructured photovoltaic devices. The usual method for attaching the nanocrystals to the titanium dioxide substrate is by means of a linking molecule (such as mercaptopropionic acid) or in-situ growth. In this paper, we report the use of an alternative technique, electrophoretic deposition (EPD), to directly deposit already formed CdSe nanocrystals onto the substrate. In EPD, a voltage is established between two electrodes that are immersed in a solution of nanocrystals. At room temperature, a fraction of the nanocrystals are thermally charged, and these charged nanocrystals migrate to the electrodes and adhere to the surface. A significant advantage of EPD over the use of linking molecules is the speed with which the nanocrystals are deposited: EPD takes only a few minutes, compared to the several hours required for the alternative techniques. Additionally, we have fabricated initial photovoltaic devices based on electrophoretically deposited CdSe nanocrystals on a planar TiO2 thin film.

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