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Solar cell nanostructures antireflective films

Solar cell nanostructures antireflective films. Chelyabinsk 2010. Solar cell.

fitzgerald-benjamin
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Solar cell nanostructures antireflective films

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  1. Solar cell nanostructures antireflective films Chelyabinsk 2010

  2. Solar cell A solar cell or photovoltaic cell is a devise that converts directly into electricity by the photovoltaic effect. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the light source is unspecified. Assemblies of cells are used to make solar panels, solar modules, or photovoltaic arrays. Photovoltics is the field of technology and research related to the application of solar cells in producing electricity for practical use. The energy generated this way is an example of solar energy (also called solar power).

  3. PV panels • Mostly Silicon • Crystalline, Microcrystalline, Amorphous, Thin Film

  4. Schedule of growth of efficiency cell

  5. Solar cell efficiency factors Energy conversion efficiency A solar cell’s energy conversion efficiency  is the percentage of power converted (from absorbed light to electrical energy) and collected, when a solar cell is connected to an electrical circuit. This term is calculated using the ratio of the maximum power point, Pm, divided by the input light irradiance (E, in W/m2) under standard test conditions (STC) and the surface area of solar cell (Ac in m2).

  6. Solar cell efficiency factors STC specifies a temperature of 25C and an irradiance of 1000 W/m2 with an air mass 1.5 (AM1.5) spectrum. These correspond to the irradiance and spectrum of sunlight incident on a clear day upon a sun-facing 37-tilted surface with the sun at an angle of 41.81 above the horizon. This condition approximately represents solar noon near the spring and autumn equinoxes in the continental United States with surface of the cell aimed directly at the sun. Thus, under these conditions a solar cell of 12% efficiency with a 100 cm2 (0.01 m2) surface area can be expected to produce approximately 1.2 watts of power.

  7. Scheme of distribution of losses of energy in the silicon cell ≈ 30%Light losses ≈25%Losses on a current ≈30%Losses on a voltage

  8. Mathematical modeling An original theoretical approach based on the concept of the effective polarizability of the valence electrons in spherical nanoparticles, which allows to predict many of the unusual properties of the composite films, which were then detected in our experimental work.

  9. Subject invention • The subject invention is a nanostructured solar cell with efficiency over 35% • The subject invention is the synthesis of nanotechnology and materials based on metal-polymer composite films, which allows the following specifications.

  10. Stabilization of the surface of metal nanoparticles of the polymer film. • Electrical neutrality of metal nanoparticles, which makes metal-polymer composite film dielectric film. • Metal nanoparticles have spherical shape.

  11. Highmonodispersed composite film, the radii of nanoparticles are predominantly 2.25 nm. (b) (а) Scan 100x100 nm metal-polymer composite film, obtained by using a transmission electron microscope JEM 100B (JEOL) at 75 kV (a). The distribution function of metal nanoparticles in size (b).The diameter of spherical nanoparticles of d = 2a. The weight content of metal in a polymer film of about 1%.

  12. Same structure of metal nanoparticles without the polymorphism is illustrated in the figure, which shows the spectra of X-ray analysis of metal-polymer composite films Diffraction patterns of samples of the polymer film

  13. Diffraction pattern of the sample 10 wt% of metal-polymer composite film.

  14. Diffraction pattern of the sample 20 wt% of metal-polymer composite film.

  15. Constant volume concentration of metal nanoparticles in a polymer film. Education nanoagregatov packed, largely providing the necessary optical properties obtained optical materials based on metal-polymer composite films.

  16. Model of the unit of spherical metal nanoparticles in the metal-polymer composite film. The origin is in the center of the spherical particles inside the aggregate of 21 particles.

  17. The thickness of the metal-polymer composite films from 10 to 100 microns. The developed technology for synthesis of metal-polymer composite films allows us to obtain very thin films with a thickness of about 100 nm. Given the optical properties of the metal-polymer composite films, one could argue that is possible to synthesize a new class of nanomaterials, which can be achieved by changing the refractive index in a wide range of values, due to restructuring in the arrangement of nanoparticles in a polymer film.

  18. We observe experimentally giant photovoltaic effect is based on the use of metal-polymer composite films with low refractive index and a small measure of absorption, ie This new material. Indeed, insulators and semiconductors have a large refractive index and low absorption. Metals, on the contrary, have a small ,but great . Thus, the massive silver at the wavelength has,

  19. Based on an analysis of the transmission spectra can be concluded that the addition of metal nanoparticles in the polymer film makes the film of the polymer in ultra-composite film, the absorption is about 10-4 in a broad optical spectrum. The transmission patterns of pure polymer films with thickness of 50 microns on glass and metal-polymer composite film with a weight content of 10% of the metal thickness of 50 microns on glass. The numbers denote: 1 - sample of metal-polymer composite films with metal nanoclusters thickness of 50 microns on a glass substrate, 2 - glass, 3 - metal-polymer composite film thickness of 50 microns on a glass substrate.

  20. Spectral signal detector for the structures of pure polymer films on glass and metal-polymer composite film on glass substrate. The thickness of the substrate from chemical glass 1 mm. The numbers denote: 1 - the atmospheric channel, 2 - metal-polymer composite film thickness of 50 microns, 3 - polymer film thickness of 10 microns, 4 - transmission of the glass without coating. The transmission of the structure, polymer with metal nanoclusters on the glass "is different from the transmission of light in free atmospheric channel. This means that for an observer under this structure, it is invisible, though the glass has a small chemical light transmission.

  21. The spectra of reflection from the surface of the cells of the photocell with illuminating film nanocomposite (1), amorphous silicon (2) and aluminum mirror (3).

  22. The spectra of reflection from the surface of cells of amorphous silicon photocell (1) and cells with photocell enlightening film nanocomposite (2).

  23. Analysis of the spectrum of reflection from the surface of solar cells with illuminating nanocomposite film shows that the refractive index of metal-polymer composite film thickness of 50 microns is

  24. Metal-polymer composite films are broad-reflective coatings for optical surfaces of transparent and opaque optical media. The film thickness can be chosen in the range of 10 to 100 microns, and the region of the optical illumination, for example, silicon ranges from 450 to 1100 nm. air film Silicon (Si)

  25. Principle of optical illumination on the basis of optical materials (polymer + metal) differs from the principle of optical interference of enlightenment, where the thickness of the interference film is only a fraction of a micrometer, and the area of enlightenment unconditional , where - the thickness of the optical interference anti -reflective coating - its refractive index,            The refractive indices of media framing.This means that the interference enlightenment is possible only in a small region of wavelengths.

  26. Principle of broadband optical illumination on the basis of new transparent optical materials with quasi-zero value of the refractive index and absorption is based on the condition , (*) where in the case of normal incidence of external radiation Fresnel coefficients , Upon reaching the zero value of the indices of absorption and refraction of the film from new material (polymer + metal) can provide an ideal illumination optical surfaces of optical media. The condition of an ideal optical illumination is defined by (*).

  27. In a perfect optical illumination reflected wave amplitude, and hence the reflectivity of the surface of the semi-infinite medium of the optical medium vanishes • If the underlying environment is transparent, that is, a weakly absorbing medium, then in an ideal optical bleaching of metal-polymer composite film becomes ultra, that is invisible to an observer located above the film. • If the underlying medium is absorbing, then in an ideal optical illumination, the observer, located above the film, will perceive the underlying environment as a black body.

  28. In a perfect optical illumination optical properties of the anti-reflective coating does not depend on the optical properties of the underlying environment. This means that such an antireflective coating is universal and can be used for optical bleaching the surface of media from various materials, including materials with strong dispersion-dependent dielectric constant.

  29. Application of metal-polymer composite films for optical bleaching the surface of silicon solar cells leads to a significant increase in their effectiveness. Changing the weight content of metal in the metal-polymer composite films leads to a giant photovoltaic effect, where the photovoltage photocell increases repeatedly.

  30. As a result of the experiments reached a record value of more than 35% efficiency of solar cells, due to a giant photovoltaic effect in silicon, covered with a metal-polymer composite films with metal nanoparticles.

  31. Test solar cell Measurement of optical characteristics of solar cells 1. The purpose of the experiment: measurement of the solar cells (№ 4) № 41 of 11.09.09.2. Used instruments:a) Laterite;b) OBC-1 device with deskside of optical fiber (voltage 155 V);c) attachment to an optical fiber for fixing the distance between the fiber and solar cells (8 mm diameter exit);d) Voltmeter and ammeter.

  32. Fig. 1 used schematic diagram of the measuring stand. 3. Measurements:a) Definition of hardware values:Rdark ~ 380 (Ohm)RAmmeter = 14 (Ohm)b) Measurement of the solar battery on the design of Fig. 1, the inverse of the solar cells:

  33. 4. Abbreviations used:R dark - resistance of solar cells without light;

  34. Conclusions The effect of a giant amplification of light in metal-polymercomposite coatings was found and proved experimentally that holds great promise for the use of metal-polymer composite coatings to improve the efficiency of silicon solar cells.Today we received a solar cell efficiency above 35%

  35. Thank You !

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