SILICON NANOWIRE SOLAR CELLS EBOOK!
Overview of advantages and fabrication of solar cells made from silicon nanowires. IT includes few slides of conventional solar cells and. ABSTRACT: Silicon nanowire solar cells with heterojunctions were prepared on single crystalline silicon wafers. The nanowire arrays were generated by silver. Vertically aligned silicon nanowire (SiNW) solar cells have already been shown theoretically to be much less sensitive to impurities, have low reflective losses.
|Published:||7 May 2014|
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Nanowire-based Solar Cells – Peidong Yang Group
The ohmic contact was formed by scratching InGa alloy at the sample backside. The schematic process for the Si NW solar cells is present in Figure 1.
Schematic illustration of the fabrication process for preparing Si NW arrays-based solar cells. Results and Discussion Figure 2 a shows the planar image of Ag nanoparticles deposited on silicon substrates via silicon nanowire solar cells electroless metal deposition method.
It is obvious that Ag nanoparticles have formed a network. It can be seen that some areas of Ag are caved in, and the silicon areas protrude outward from the interspaces among the Ag nanoparticles.
It indicates that the silicon parts under the Ag nanoparticles are etched off and then the shallow pits form due to the catalytic role of Ag, and the silicon uncovered with Ag remains almost unchanged.
After etching for a longer time, the Silicon nanowire solar cells NWs can be created as the Ag nanoparticles continue to sink.
Figures 2 c and 2 d show the planar and the cross-sectional views, respectively, of the Si NW arrays.
As can be seen from the SEM micrographs, these Si nanowires are tangled with each other and hold together in bundles. This phenomenon could be caused by capillary action during the drying process due to the high aspect ratio of silicon silicon nanowire solar cells.
The diameter of silicon nanowires generally ranges from 40 to nm.
Note that the silver particles could be found to lie at the bottom of the Si NWs, as shown in Figure 2 e. It indicates that the diameter of individual nanowire is roughly uniform. Figures 3 a — 3 e demonstrates the cross-sectional SEM micrographs of Silicon nanowire solar cells NW arrays with different length fabricated at 0.
The SEM observation clearly revealed that the lengths of the produced Si NWs increased with the etching time, ranging from nm to nm, which indicates that the length of the Si NWs can effectively be tailored by prolonging the etching time.
Figure 3 f shows the Si NW length as a function of the etching time.
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An excellent linear behavior can be obtained. The etching rate can be evaluated to be about Cross-sectional images and length of Si NWs etched for different time. Figure 4 shows the reflectance of Si NWs silicon nanowire solar cells polished wafer as a function of light wavelength.
It can be seen that the as-grown Si NW arrays exhibit not only a large suppression of the reflectance over the entire light wavelength range, but also a very different reflection behavior from polished Si.
Performance of Silicon Nanowire Solar Cells with Phosphorus-Diffused Emitters
The reflectance decreases with the wavelength increasing. This can be attributed to the three important properties of Si NW arrays. One is the extremely high surface area of the Si NW arrays. We have introduced a new version of the dye-sensitised cell in which the traditional nanoparticle film is replaced by a dense array of oriented, crystalline ZnO nanowires.
The direct electrical pathways provided by the nanowires ensure the rapid collection of carriers silicon nanowire solar cells throughout the device, and a full Sun efficiency of 3. We are now extending our synthetic strategy to design nanowire electrodes with much larger areas available for dye adsorption.
It is worth noting that the advantages of the nanowire geometry are even more compelling for other types of excitonic photocells, such as inorganic-polymer, inorganic composite hybrid devices, in which an oriented, continuous and crystalline inorganic phase could greatly improve charge collection.
- Journal of Nanomaterials
- Performance of Silicon Nanowire Solar Cells with Phosphorus-Diffused Emitters