US 2009/0253227 A1 · ENGINEERED OR STRUCTURED COATINGS FOR LIGHT MANIPULATION IN SOLAR CELLS AND OTHER MATERIALS

Abstract

The present disclosure concerns a means to design, engineer and use antireflective or metallo-dielectric coatings incorporating metallic, nonmetallic, organic and inorganic metamaterials or nanostructures to manipulate light in solar thermal and photovoltaic materials. Such metallic, nonmetallic, organic or inorganic metamaterials or nanostructures could be used to manipulate light for photovoltaic effects on or in any material or substrate. Dielectric coatings containing metallic nanostructures could be used to improve the efficiency of solar cells and to influence or control such characteristics as optical and thermal absorption, conduction, radiation, emissivity, reflectivity and scattering.

Claims16

Dependent claims

A method of combining transparent nanopatterned metallic structures or thin-film as contacts or electrodes to create organic or inorganic photovoltaic subcells or multijunction stacks:

where at least subcells or multijunction stacks can be spectrally or optically tuned,
where at least absorption properties may be enhanced through the conductivity of transparent metal contacts,
where at least the resulting structures can be engineered to incorporate all the features and functions required to operate independently as a solar cell and may be deposited on or combined with any substrate.

A method of using nanostructured metallo-dielectric coatings to boost the efficiency of solar harvesting devices (Photovoltaic and Thermal):

where at least coatings effectively reduce back-reflection of light over a broad wavelength range,
where at least coatings promote forward scattering of light into oblique directions that more strongly interact with the active medium such as waveguide modes in thin solar cells,
where at least coatings enable light concentration in those regions of the cell where light absorption most efficiently produces current, e.g. in the pn-junction or near a donor acceptor interface,
where at least a cell or substrate (Photovoltaic or Thermal) is coated with a metallo-dielectric coating where the layer consists of dielectric elements and metallic nanostructures and the total thickness and composition of the coating is optimized to reduce back-reflection of light over a broad wavelength range,
where at least subwavelength metallic nanostructures can enable local light concentration and scattering into oblique angles for coupling into waveguide modes.

2 more elements

A method of simulation, optimization and design for the net overall absorption of a thin film solar cell over the entire solar spectrum:

where at least light absorption could be improved in ultra-thin layers of active material it would lead directly to lower recombination currents, higher open circuit voltages, and higher conversion efficiencies,
where at least this could simultaneously take advantage of the high near-fields surrounding the nanostructures close to their surface plasmon resonance frequency and the effective coupling to waveguide modes supported by the active layers through an optimization of the array properties,
where at least it is possible to use a simple model system consisting of a periodic array of metal particles on a thin spacer layer on a thin semiconductor film supported by a substrate to illustrate these concepts,
where at least individual components of the cell structure are selected,
where at least the metal particle geometry can effectively concentrate light in its vicinity at frequencies near its surface plasmon resonance,
where at least resonance frequency critically depends on the particle geometry and its dielectric environment.

3 more elements

Dependencies are inferred from the claim text.

Engineered or structured coatings for light manipulation in solar cells and other materials

Life of this patent

Engineered or structured coatings for light manipulation in solar cells and other materials

Life of this patent

Abstract

Claims16