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In order to increase the efficiency of solar cell modules it is necessary to make the optimum use of light incident upon them. Much research has been done on im-proving light absorption through front surface texturisation and light trapping schemes. Laser light is commonly used in industry for various applications including marking and texturisatio...
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... Solar, String RibbonTM wafers) were diced into eight by eight millimetres sections using a 355 nm pulsed nanosecond laser (Blueacre Technology). The front and rear contacts were soldered to the cells, and they were then encapsulated in an elastic transparent resin (ACC Silicones, QSil 216) and allowed to set at room temperature for 24 hours (see Fig. ...
Context 2
... lar, String RibbonTM wafers) were diced into eight by eight millimetres sections using a 355 nm pulsed nanosecond laser (Blueacre Technology). The front and rear contacts were soldered to the cells, and they were then encapsulated in an elastic transparent resin (ACC Silicones, QSil 216) and allowed to set at room temperature for 24 hours (see Fig. ...
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In this paper, we used UV micro-imprint lithography periodic patterning combined with self-textured BZO films with a wide range of texture distributions for light trapping in thin-film silicon solar cells. It was found that the feature size of the periodic textures has a significant influence on the light trapping capacity of the glass substrate an...
In order to increase the efficiency of solar cell modules it is necessary to make the optimum use of light incident upon them. Much research has been done on improving light absorption through front surface texturisation and light trapping schemes. Laser light is commonly used in industry for various applications including marking and texturisation...
In order to increase the efficiency of solar cell modules it is necessary to make the optimum use of light incident upon them. Much research has been done on improving light absorption through front surface texturisation and light trapping schemes. Laser light is commonly used in industry for various applications including marking and texturisation...
Recently, selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In this study, we presented a novel technique for the SE formation by controlling the surface morphology of Si wafers. SEs were formed simultaneously,...
Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a p...
Citations
... Despite excimer ultra-short (i.e., pulse width in the femtosecond to picosecond range) lasers provide high-precision material processing with crack-and almost debris-free surfaces and high precision profiles with respect to nanosecond or longer laser pulses [32][33][34], the related highly expensive instrumentation favored spreading use of economic (relatively simple equipment and low capital investment) microsecond-pulsed carbon dioxide (CO 2 ) laser sources operating at wavelengths strongly absorbed by glasses [28,30,35]. Hence, although limited to the realization of micro-sized structures (since heat dissipation in the surrounding material during the photo-thermal process influences the spatial resolution), nowadays CO 2 laser-based ablation/micro-machining represents a serial method to engrave patterns on glass materials (such as quartz, borofloat and pyrex) [35] that have found applications in solar cells to enhance light trapping efficiency [36]. ...
Carbon dioxide (CO2)-laser processing of glasses is a versatile maskless writing technique to engrave micro-structures with flexible control on shape and size.
In this study, we present the fabrication of hundreds of microns quartz micro-channels and micro-holes by pulsed CO2-laser ablation with a focus on the great potential of the technique in microfluidics and biomedical applications. After discussing the impact of the laser processing parameters on the design process, we illustrate specific applications. First, we demonstrate the use of a serpentine microfluidic reactor prepared by combining CO2-laser ablation and post-ablation wet etching to remove surface features stemming from laser-texturing that are undesirable for channel sealing. Then, cyclic olefin copolymer micro-pillars are fabricated using laser-processed micro-holes as molds with high detail replication. The hundreds of microns conical and square pyramidal shaped pillars are used as templates to drive 3D cell assembly. Human Umbilical Vein Endothelial Cells are found to assemble in a compact and wrapping way around the micro-pillars forming a tight junction network. These applications are interesting for both Lab-on-a-Chip and Organ-on-a-Chip devices.
... Structures for the optical path enhancement can be fabricated using processes, such as etching, laser imprinting, diamond micro-grinding, and UV imprinting [54,[59][60][61][62][63][64][65][66][67][68]. ...
Demand for renewable energy continually increases due to environmental pollution and resource depletion caused by the increased use of fossil fuels. Among the various renewable energies, the solar cell developed by numerous researchers has been widely used because of its advantages, including ease of use and low maintenance cost. However, problems, such as efficiency, waste treatment, and light pollution, also raise concerns. The largest drawback of solar cell has been the low energy conversion efficiency arising from optical loss. To improve solar cell efficiency, numerous studies have been conducted, and thus, various solutions were developed in recent decades. In this review, the principle and application of surface texturization methods utilizing micro/nano scale structure on the surfaces of solar cells are elaborated in detail. These texturized surfaces with unique optical properties can be implemented as anti-reflective or light-trapping interfaces to reduce optical loss and thus enhance the efficiency of solar cells. Optical properties of texturized surfaces and applied examples are introduced in this review.
... The morphology of these textures is interrelated to the thickness of the film and it is hard to obtain a multi-scale textures with different ranges of sizes or shapes in one step. Recently, reactive ion etching (RIE) and laser-based techniques were used to texturize glass to obtain multi-scale textures with two different ranges of texture sizes (Janthong et al., 2013;Moore et al., 2013). Using this textured glass, a-Si:H/lc-Si:H tandem cells with initial efficiencies of 13.3% and 14.4% were reported (Tan et al., 2013;Kroll et al., 2011). ...
This paper reports a facile method to prepare a textured surface with combined micron- and nano-scale surface features, which is used as master for nano-imprinting process to obtain transparent front electrodes in thin-film silicon tandem cells. The micron- and nano-scale surface features of the master are formed by combination of SiO2 sphere pre-deposition and ZnO textured growth. The master exhibits an averaged total transmittance value of 89.7% and an averaged haze value of 54.1% for the wavelength from 380 to 1100 nm. Comparing to the flat reference cell, the thin-film Si tandem cell deposited on the superstrate prepared using this master shows substantial decrease in reflectance at long wavelengths and drastic gain in the photocurrent of the bottom cell, the maximum summed current is enhanced by 35.5%, and the convert efficiency is improved from 8% to 10.0 ± 0.3%.
... For example, by smoothing surface morphology, the optical transmission in a solar cell can be improved. (24) In this work, the changes in the surface state after deposition of acrylic coatings enable a decrease in reflectionion and light scattering. As a consequence, the transmission of light energy is enhanced. ...
... For example, by smoothing surface morphology, the optical transmission in a solar cell can be improved. (24) In this work, the changes in the surface state after deposition of acrylic coatings enable a decrease in reflectionion and light scattering. As a consequence, the transmission of light energy is enhanced. ...
The damage provoked by sand storms in Sahara desert to windscreen of vehicles and solar mirrors is a problem. Different solutions have been proposed, one of them is the application of polymeric coatings, but they rapidly degrade. In this work, we have deposited silica-based sol-gel coatings including silica nanoparticles onto sandblasted glasses. The glasses were eroded by sandblasting varying the projected sand mass and the incidence angle to obtain different surface states. The eroded samples were coated by dipping with a silica layer to correct the defects induced by sandblasting and restore the optical transmission.
The damage increases with increasing projected mass and the impact angle. The optical transmission decreases with increasing damage. In extreme conditions, optical transmission falls from 91.5% to 68.6%. The deposition of silica-based layers containing SiO2 colloidal nanoparticles promotes the repairing of sandblasting defects. A strong decrease of roughness to values similar to those of as-received glass is related with the increasing of the optical transmission up to levels permitting of windscreens and solar mirrors. Transmittance measurements showed a remarkable improvement in all cases, whatever the projected sand mass or the impact angle. For highly degraded samples, the transmission increases from 68.6% to 91.4%, an improvement of near 23%.
... For example, by smoothing surface morphology, the optical transmission in a solar cell can be improved. (24) In this work, the changes in the surface state after deposition of acrylic coatings enable a decrease in reflectionion and light scattering. As a consequence, the transmission of light energy is enhanced. ...
The aim of this work is to investigate the effect of acrylic coatings on the optical and mechanical properties of sandblasted soda–lime–silica glass. The results show that sandblasting causes a considerable drop in the optical transmission of soda–lime–silica glass (T∼15%) and alters its visibility. The glass strength decreases from 80 to about 24 MPa. The photovoltaic efficiency of a solar cell covered with a sandblasted glass drops below 90%. With use of an acrylic coating, significant improvements in optical transmission (87%) and photovoltaic efficiency (98%) were recorded and a clear enhancement of visibility was noticed. The mechanical strength improvement obtained with the coating was, however, better on samples previously etched with hydrofluoric acid (HF). Impact fatigue resistance tests showed that sandblasting causes a decrease from 13 to three cycles (number of strikes leading to fracture) and an increase up to ∼28 cycles with HF-etching. After depositing an acrylic coating, a significant improvement of the impact fatigue resistance was achieved (∼129 cycles and ∼198 cycles with a single and a double layer coating, respectively).
The power of a PV module affects the amount of incident light collected by the cells. It causes optical loss in the process of modularizing solar cells. Optical loss in the PV module is reflected due to refractive index mismatch at the air/glass interface. To reduce the optical loss, we form periodic patterns using a femtosecond laser, which is a non-thermal process and form various patterns through a chemical etching process. The laser patterned glass having a light-trapping structure with a periodic pattern improved transmittance of 1.59% in the visible ray region (380–780 nm) and haze ratio of 55% at 550 nm. Laser patterned glass was applied to the module, and the power was improved by 1.56% with a current gain of 1.56% due to the light-trapping structure.
In this work we investigate the use of a picosecond (ps) laser used for monolithic connection to pattern glass substrates to achieve light in-coupling in silicon thin film solar cells. We present our results on the patterning of three commercially available and frequently used multi-component glasses Corning EAGLE XG®, Schott BOROFLOAT® 33 and Saint-Gobain SGG DIAMANT®. We find that the different glass structural components influence the degree of texturing obtained. This can be attributed to the different laser induced electron collision times and recombination rates, and thus the critical electron density evolution leading to ablation. Thus the ablated crater profile is glass composition dependent. The surface texture is altered from periodic to random with decreasing scribing speed. The transmission of the textured substrates gradually decreases while the reflection increases as a consequence of the topological and morphological changes. The angular resolved measurements illustrate that highly textured substrates scatter the light towards greater angles. This demonstrates potential for the application in substrate configuration (nip) thin film solar cells, as the scattering can increase the optical path, and hence the absorption in the absorber layer. Simulations of periodically textured glass substrates demonstrate a focused optical generation rate near the front contact and absorber layer interface. The influence of the modified refractive index region on the optical generation rate and reflection depends on the crater profile. The reflection is generally reduced when a periodic texture in the micrometre range is implemented.
