scholarly journals Long Wavelength Plasmonic Absorption Enhancement in Silicon Using Optical Lithography Compatible Core-Shell-Type Nanowires

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammed Shahriar Sabuktagin ◽  
Khairus Syifa Hamdan ◽  
Khaulah Sulaiman ◽  
Rozalina Zakaria ◽  
Harith Ahmad
Keyword(s):  
Thin Film ◽  
Photovoltaic Effect ◽  
Optical Lithography ◽  
Absorption Enhancement ◽  
Core Shell ◽  
Ohmic Loss ◽  
Long Wavelength ◽  
Enhanced Absorption ◽  
Shell Type ◽  
Thin Film Silicon

Plasmonic properties of rectangular core-shell type nanowires embedded in thin film silicon solar cell structure were characterized using FDTD simulations. Plasmon resonance of these nanowires showed tunability from  nm. However this absorption was significantly smaller than the Ohmic loss in the silver shell due to very low near-bandgap absorption properties of silicon. Prospect of improving enhanced absorption in silicon to Ohmic loss ratio by utilizing dual capability of these nanowires in boosting impurity photovoltaic effect and efficient extraction of the photogenerated carriers was discussed. Our results indicate that high volume fabrication capacity of optical lithography techniques can be utilized for plasmonic absorption enhancement in thin film silicon solar cells over the entire long wavelength range of solar radiation.

Light Trapping in Thin Film Silicon n-i-p Solar Cells - Gains and Losses

2008 ◽  
Vol 1101 ◽  
Author(s):  
Ruud E.I. Schropp ◽  
Hongbo Li ◽  
Jatin K. Rath ◽  
Ronald H. Franken
Keyword(s):  
Thin Film ◽  
Light Trapping ◽  
Structural Defects ◽  
Metallic Surface ◽  
Textured Surfaces ◽  
Long Wavelength ◽  
Thin Film Silicon ◽  
Internal Surfaces ◽  
Gains And Losses ◽  
Wavelength Light

AbstractThin film silicon solar cell technology frequently makes use of rough or textured surfaces in order to enhance light absorption within the thin absorber layers by scattering and total internal reflection (“light trapping”). The rough morphology of the optically functional internal surfaces both in superstrate and substrate cells however, not only has a beneficial effect on light scattering properties, but on the other hand may also have deleterious effects on the microscopic structure of the deposited layers, in particular if these layers are nanocrystalline. The narrow valleys in the surface morphology may lead to structural defects, such as cavities and pinholes. By adjusting the morphology, these defects can be avoided.However, even when structural defects in layers directly deposited on rough interfaces are avoided, the obtained optically defined maximum current density is still much lower than expected. For instance, in n-i-p structures the rough interface (the textured back reflector consisting of nanostructured Ag coated with ZnO) is located at the back of the cell, where only long wavelength light is present. The natively textured Ag film is sputtered at elevated temperature and optimized for diffusely reflecting this long wavelength light. From experiments we infer that the nanostructured metallic surface also gives rise to plasmon absorption in the red and near IR, and that this leads to a parasitic absorption, i.e. at least part of the absorbed energy is not re-emitted to the active layers.

Light-trapping in Thin Film Silicon Solar Cells with a Combination of Periodic and Randomly Textured Back-reflectors

2012 ◽  
Vol 1426 ◽  
pp. 117-123 ◽  
Author(s):  
Sambit Pattnaik ◽  
Nayan Chakravarty ◽  
Rana Biswas ◽  
D. Slafer ◽  
Vikram Dalal
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Light Absorption ◽  
Nanoimprint Lithography ◽  
Light Trapping ◽  
Silicon Solar Cells ◽  
Long Wavelength ◽  
Thin Film Silicon ◽  
Back Reflectors ◽  
Back Reflector

ABSTRACTLight trapping is essential to harvest long wavelength red and near-infrared photons in thin film silicon solar cells. Traditionally light trapping has been achieved with a randomly roughened Ag/ZnO back reflector, which scatters incoming light uniformly through all angles, and enhances currents and cell efficiencies over a flat back reflector. A new approach using periodically textured photonic-plasmonic arrays has been recently shown to be very promising for harvesting long wavelength photons, through diffraction of light and plasmonic light concentration. Here we investigate the combination of these two approaches of random scattering and plasmonic effects to increase cell performance even further. An array of periodic conical back reflectors was fabricated by nanoimprint lithography and coated with Ag. These back reflectors were systematically annealed to generate different amounts of random texture, at smaller spatial scales, superimposed on a larger scale periodic texture. nc-Si solar cells were grown on flat, periodic photonic-plasmonic substrates, and randomly roughened photonic-plasmonic substrates. There were large improvements (>20%) in the current and light absorption of the photonic-plasmonic substrates relative to flat. The additional random features introduced on the photonic-plasmonic substrates did not improve the current and light absorption further, over a large range of randomization features.

Quasi-crystal photonic structures for fullband absorption enhancement in thin film silicon solar cells

2018 ◽  
Vol 175 ◽  
pp. 41-46 ◽  
Author(s):  
Peizhuan Chen ◽  
Pingjuan Niu ◽  
Liyuan Yu ◽  
Jianjun zhang ◽  
Qihua Fan ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Absorption Enhancement ◽  
Silicon Solar Cells ◽  
Photonic Structures ◽  
Thin Film Silicon

Asymmetric metasurface structures for light absorption enhancement in thin film silicon solar cell

2019 ◽  
Vol 21 (4) ◽  
pp. 045901 ◽  
Author(s):  
Hengchang Lu ◽  
Xiaowei Guo ◽  
Juan Zhang ◽  
Xizheng Zhang ◽  
Shaorong Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Light Absorption ◽  
Silicon Solar Cell ◽  
Absorption Enhancement ◽  
Thin Film Silicon

Surface-Plasmon Enhanced Near-Bandgap Light Absorption in Silicon Photovoltaics

2008 ◽  
Author(s):  
Lu Hu ◽  
Xiaoyuan Chen ◽  
Gang Chen
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Light Trapping ◽  
Large Fraction ◽  
Solar Spectrum ◽  
Silicon Solar Cells ◽  
Long Wavelength ◽  
Thin Film Silicon ◽  
Silicon Photovoltaics ◽  
Silicon Based

One key challenge for silicon-based solar cells is the weak absorption of long-wavelength photons near the bandgap (1.1eV) due to the indirect bandgap of silicon. A large fraction of the AM 1.5 solar spectrum falls into a regime (0.7 μm – 1.1 μm) where silicon does not absorb light well. The capture of these long-wavelength photons imposes a particular problem to the thin-film silicon solar cells. For this reason, thin-film silicon solar cells often incorporate some forms of light trapping mechanisms.

N-type Microcrystalline Silicon Oxide (μc-SiOx:H) Window Layers with Combined Anti-reflection Effects for n-i-p Thin Film Silicon Solar Cells

2010 ◽  
Vol 1245 ◽  
Author(s):  
Vladimir Smirnov ◽  
Wanjiao Boettler ◽  
Andreas Lambertz ◽  
Oleksandr Astakhov ◽  
Reinhard Carius ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Silicon Oxide ◽  
Window Layer ◽  
Silicon Solar Cells ◽  
Internal Electric Field ◽  
Microcrystalline Silicon ◽  
Side Window ◽  
Long Wavelength ◽  
Thin Film Silicon

AbstractWe will describe the development and application of n-type microcrystalline silicon oxide (μc-SiOx:H) alloys as window layers in thin film silicon solar cells with microcrystalline silicon (μc-Si:H) absorber layers. Cells are prepared in n–i–p deposition sequence with illumination through the n-side. The layers were deposited by radio-frequency plasma enhanced chemical vapour deposition (RF-PECVD) at 185°C substrate temperature, using a mixture of phosphine (PH3), silane (SiH4), carbon dioxide (CO2) and hydrogen (H2) gases, at CO2 flows varied between 0.5 and 2 sccm and different thickness. Films were characterised by dark conductivity measurements, Photothermal Deflection Spectroscopy (PDS) and Raman spectroscopy to evaluate optical band gap E04, refractive index n and crystallinity ICRS, respectively. The results were compared with the data of alternative optimised window layers, such as n-type μc-Si:H and silicon carbide (μc-SiC:H) films. Also solar cells with conventional illumination through the p-side window were investigated for comparison. Solar cells were prepared with μc-SiOx:H n-layers of varied compositions and characterised by current-voltage (J-V) measurements under AM 1.5 illumination (and also under modified AM 1.5 illumination with red (OG590) and blue (OG7) filters) and reflectance measurements. The effects of the μc-SiOx n-layer composition and thickness on the performance of n-i-p cells were investigated and correlated with the optical, electrical and structural properties of the μc-SiOx:H n-layers. The results indicate that n-type μc-SiOx:H provides a sufficient combination of conductivity (up to 0.1 S/cm) and crystallinity (ICRS up to 30%) to function well as a doped layer for the internal electric field and the carrier transport and as a nucleation layer for the growth of the μc-Si:H i-layer. As a window layer, it also results in an enhanced spectral response, particularly in the long wavelength part of the spectrum of the solar cells, in comparison with the cells containing alternative window layers. An improved short circuit current density (Jsc) can be attributed to the wide optical gap E04 (around 2.3 eV) in the μc-SiOx:H window layers and reduced reflection in the long wavelength region of the spectrum. A minimum total reflectance of only 6% at 570nm wavelength was achieved with such μc-SiOx:H window layers. Using optimised n-type μc-SiOx:H as a window layer, an efficiency of 8.0% for 1cm2 cell area was achieved with 1 μm thick μc-Si:H absorber layer and Ag back reflector.

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