scholarly journals Reflectance Improvement by Thermal Annealing of Sputtered Ag/ZnO Back Reflectors in a-Si:H Thin Film Silicon Solar Cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
Karin Söderström ◽  
Franz-Josef Haug ◽  
Céline Pahud ◽  
Rémi Biron ◽  
Jordi Escarré ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Thermal Annealing ◽  
Short Circuit ◽  
Flexible Substrate ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Polyethylene Naphthalate ◽  
Thin Film Silicon ◽  
Back Reflectors

ABSTRACTSilver can be used as the back contact and reflector in thin film silicon solar cells. When deposited on textured substrates, silver films often exhibit reduced reflectance due to absorption losses by the excitation of surface plasmon resonances. We show that thermal annealing of the silver back reflector increases its reflectance drastically. The process is performed at low temperature (150°C) to allow the use of plastic sheets such as polyethylene naphthalate and increases the efficiency of single junction amorphous solar cells dramatically. We present the best result obtained on a flexible substrate: a cell with 9.9% initial efficiency and 15.82 mA/cm2 in short circuit current is realized in n-i-p configuration.

Thermodynamic limits of nanophotonic light trapping in thin film silicon solar cells

2014 ◽  
Vol 92 (7/8) ◽  
pp. 909-912 ◽  
Author(s):  
Brian R. Maynard ◽  
E.A. Schiff
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Light Trapping ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Thin Film Silicon ◽  
Solar Tracking ◽  
Current Densities ◽  
Thermodynamic Limits

We have extended an earlier thermodynamic treatment of light-trapping in lattice-textured solar cells to higher absorptances. This treatment is used to calculate the quantum efficiency spectra and short-circuit current densities JSC for thin-film silicon solar cells with ideal lattice textures. An optimal triangular lattice period of 900 nm yields a calculated JSC that is 2 mA/cm2 larger than for ideal random textures in a 1000 nm thick cell. We compare the calculations to recent experiments with periodically textured cells. While the experimental cells give JSC values that are comparable to the best cells with conventional textures, they do not show the features associated with the prediction of higher JSC. We discuss the role of imperfections in the periodic texturing, and suggest that cells used with solar tracking may realize the predicted JSC improvement.

Thin Film Silicon Solar Cells on Transparent Plastic Substrates

2009 ◽  
Vol 1153 ◽  
Author(s):  
Ehsanollah Fathi ◽  
Andrei Sazonov
Keyword(s):  
Thin Film ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Polyethylene Naphthalate ◽  
Transparent Plastic ◽  
Plastic Substrates ◽  
Thin Film Silicon ◽  
Open Circuit Voltages

AbstractIn this work, we optimized different thin film silicon layers in a single junction p-i-n solar cell at deposition temperature of 150 °C. Using the optimized doped and undoped layers, 0.5 cm2 test cells fabricated both on glass and polyethylene naphthalate (PEN) substrates. The cells show identical open circuit voltages and fill factors, whereas the short circuit current and consequently the efficiency of the cell fabricated on glass is higher than the efficiency of 3.99% of the cell fabricated on PEN substrate.

Thin-film silicon solar cells applying optically decoupled back reflectors

2013 ◽  
Vol 178 (9) ◽  
pp. 645-650 ◽  
Author(s):  
E. Moulin ◽  
U.W. Paetzold ◽  
K. Bittkau ◽  
M. Ermes ◽  
L. Ding ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Silicon Solar Cells ◽  
Thin Film Silicon ◽  
Back Reflectors

Improved light trapping effect for thin-film silicon solar cells fabricated on double-textured white glass substrate

2014 ◽  
Vol 92 (7/8) ◽  
pp. 920-923 ◽  
Author(s):  
Hidetoshi Wada ◽  
Keiichi Nishikubo ◽  
Porponth Sichanugrist ◽  
Makoto Konagai
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Light Trapping ◽  
Short Circuit ◽  
Silicon Solar Cells ◽  
Organic Chemical ◽  
Trapping Effect ◽  
Thin Film Silicon ◽  
Vapor Deposition Technique

Light trapping effect using rough surface transparent conductive oxide (TCO) is one of the best ways to achieve high efficiency thin-film silicon solar cells. Several types of rough ZnO film fabricated by metal organic chemical vapor deposition technique onto the glass, which are etched by reactive ion etching, have been proposed so far as promising TCO substrates. In this paper, newly developed ZnO substrate with extremely high light scattering property comparing with typical pyramidal texture one was developed. By applying this newly developed ZnO substrate to the solar cell, higher short circuit current of about 2% has been achieved comparing with typical pyramidal texture one without sacrificing other parameters. This result showed that the newly developed substrate is suitable as a front TCO substrate for high performance thin-film silicon solar cell.

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.

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