Window having wavelength selectivity and photovoltaic capability
A generally transparent solar cell or solar cell array is formed on a tensioned flexible substrate located between parallel rigid transparent members. Layers are formed on the tensioned flexible substrate so as to include both filter layers which are cooperative to provide desired wavelength-filtering properties and power-generating layers which are cooperative to provide photovoltaic properties. In the embodiments in which the power-generating layers form an organic solar cell, one or both of the spaces between the substrate and the rigid transparent members contain a fixed volume of gas, so that deterioration of the layers as a consequence of exposure to moisture is retarded.
1 . A window for use along a wall of a structure so as to separate an interior from an exterior of said structure, said window comprising:
parallel first and second rigid transparent members; and
a tensioned flexible substrate located between but spaced apart from said first and second rigid transparent members by fixed volumes of gas, said tensioned flexible substrate having a plurality of layers formed thereon, including filter layers which are cooperative to provide desired wavelength filtering properties and further including power generating layers which are cooperative to provide photovoltaic properties, wherein transmissivity of visible light along a path that intersects both said filter and power generating layers is at least twenty percent.
2 . The window of claim 1 wherein said power generating layers comprise materials which define an organic solar cell and wherein said fixed volumes of gas are sealed within areas between said tensioned flexible substrate and said first and second rigid transparent members.
3 . The window of claim 2 wherein said gas is primarily an inert gas.
4 . The window of claim 1 wherein said power generating layers are thin film layers which define a large area, generally transparent solar cell within a central viewing area of said window, said solar cell being an organic solar cell.
5 . The window of claim 4 wherein said power generating layers define a plurality of said generally transparent solar cells which are connected to provide electrical power that is directed from said window.
6 . The window of claim 5 wherein at least one of said filter layers which are cooperative to provide said wavelength filtering properties also functions as an electrode for said power generating layers.
7 . The window of claim 2 wherein said plurality of layers further includes reflective layers positioned to direct light to said organic solar cell.
8 . The window of claim 1 wherein at least one of said plurality of layers includes surface irregularities configured to induce light scattering that enhances efficiency of said power generating layers.
9 . The window of claim 1 wherein an exposed surface of said plurality of layers that is associated with said exterior of said structure exhibits low emissivity (a Low E surface) with respect to radiation of heat.
10 . A window separating the interior from the exterior of a structure comprising:
three parallel substrates in which a center substrate is spaced apart from end substrates by areas of trapped gas, said end substrates being transparent and being rigid, said center substrate being flexible and being transparent;
a layer stack configured for wavelength selection with respect to transmission of solar energy, said layer stack being on said center substrate to determine optical properties of said window; and
a solar cell arrangement of layers on said center substrate along a same optical path as said layer stack, said solar cell arrangement occupying at least fifty percent of the area of said center substrate, said layers defining an organic optoelectric capability.
11 . The window of claim 10 wherein a solar transmissivity through said same optical path is at least twenty percent, said solar cell arrangement being at least one solar cell having an organic photovoltaic material.
12 . The window of claim 10 wherein said layer stack includes an outer conductive layer which is cooperative with other layers of said layer stack to provide solar control, said conductive layer simultaneously being an electrode layer of said solar cell arrangement.
13 . The window of claim 10 wherein at least one said area of trapped gas contains an inert gas to retard degradation of said solar cell arrangement.
14 . The window of claim 10 wherein said solar cell arrangement comprises a plurality of organic solar cells.
15 . A window comprising:
a frame;
first and second glass panes secured in parallel relationship by said frame;
a polymeric member tensioned within said frame between said first and second glass panes such that areas of trapped inert gas reside between said polymeric member and said first and second glass panes, said polymeric member having a wide area viewing region through which transmissivity in the visible light range is at least twenty percent, said wide area viewing region having a coating thereon, said coating including a first layer sequence that forms an organic solar cell and a second layer sequence that forms a mirror positioned to direct solar energy to said organic solar cell so as to enhance efficiency of photoelectric conversion, wherein visible light through said coating has a transmissivity of at least twenty percent.
16 . The window of claim 15 wherein said second layer sequence includes a Dynamic Bragg Reflector (DBR).
17 . The window of claim 15 wherein said coating includes surface irregularities to induce light scattering so as to further enhance said efficiency of photoelectric conversion.
18 . The window of claim 15 wherein said areas of trapped inert gas contain argon.