Barrier films and high throughput manufacturing processes for photovoltaic devices

Abstract

Methods and devices are provided for improved roofing devices. In one embodiment of the present invention, a photovoltaic roofing assembly is provided that comprises of a roofing membrane and a plurality of photovoltaic cells supported by the roofing membrane. The photovoltaic cells may be lightweight, flexible cells formed on a lightweight foil and disposed as a layer on top of the roofing membrane. The roofing assembly may include at least one flexible encapsulant film that protects the plurality of photovoltaic cells from environmental exposure damage, wherein the encapsulant film is formed using a non-vacuum process. Optionally, the process may be a lamination process. In other embodiments, the process is a non-vacuum, non-lamination process. The resulting roofing membrane and the photovoltaic cells are constructed to be rolled up in lengths suitable for being transported to a building site for unrolling and being affixed to a roof structure.

1 . A photovoltaic roofing assembly, comprising:
 a roofing membrane;   a plurality of photovoltaic cells supported by the roofing membrane, wherein the photovoltaic cells are non-rigid, flexible cells; and   at least one flexible encapsulant film protecting the plurality of photovoltaic cells from environmental exposure damage, wherein the encapsulant film is formed using a non-vacuum process.   
     
     
         2 . The assembly of  claim 1  wherein the non-vacuum process is a non-vacuum, lamination process. 
     
     
         3 . The assembly of  claim 1  wherein the non-vacuum process is a non-vacuum, non-lamination process. 
     
     
         4 . The assembly of  claim 1  wherein the encapsulant film comprises of a plurality of discrete nanolaminate layers, wherein the nanolaminate layers are self-assembled in a configuration of alternating organic material layers and inorganic material layers. 
     
     
         5 . The assembly of  claim 4  wherein organic material comprises of a polymer. 
     
     
         6 . The assembly of  claim 4  wherein organic material comprises of a hydrophobic polymer. 
     
     
         7 . The assembly of  claim 4  wherein inorganic material layer consists essentially of an inorganic material. 
     
     
         8 . The assembly of  claim 1  wherein the encapsulant film comprises of fused silica beads. 
     
     
         9 . The assembly of  claim 1  wherein the encapsulant film comprises of a composite wherein a majority of the volume is occupied by particles of glass and/or other transparent inorganic material and deposited as a thin film coating over the photovoltaic cells. 
     
     
         10 . The assembly of  claim 9  wherein the particles has a shape selected from at least one of the following: spheres, platelets, flakes, ovals, cone, or combinations thereof. 
     
     
         11 . The assembly of  claim 9  wherein the encapsulant film comprises of fused particles. 
     
     
         12 . The assembly of  claim 9  wherein the particles are fused by a rapid thermal process at a temperature and/or duration that will not damage the underlying photovoltaic cells. 
     
     
         13 . The assembly of  claim 9  wherein the film is substantially without pinholes and/or microvoids. 
     
     
         14 . The assembly of  claim 1  wherein the encapsulant film includes one or more discrete layers comprising:
 i) at least a first layer having a first composition characterized by at least one of the following properties: scratch resistance, UV resistance, water diffusion resistance, or oxygen diffusion resistance; and 
 ii) at least a second layer having a second composition which exhibits at least one of the following properties more strongly than the first layer and is not a main property of the first layer: scratch resistance, UV resistance, water diffusion resistance, or oxygen diffusion resistance. 
 
     
     
         15 . The assembly of  claim 1  wherein the encapsulant film comprises a polymer. 
     
     
         16 . The assembly of  claim 1  wherein the encapsulant film comprises a transparent PVC material. 
     
     
         17 . A high throughput manufacturing method comprising:
 providing a plurality of photovoltaic cells;   coupling the cells to a roofing membrane; and   forming at least one flexible encapsulant film protecting the plurality of photovoltaic cells from environmental exposure damage, wherein the encapsulant film is formed using a non-vacuum process.   
     
     
         18 . The method of  claim 17  wherein the forming step comprises using a non-vacuum, non-lamination process to form the encapsulant film. 
     
     
         19 . The method of  claim 17  wherein the forming step comprises forming a plurality of discrete nanolaminate layers, wherein the nanolaminate layers self-assemble in a configuration of alternating organic material layers and inorganic material layers. 
     
     
         20 . The method of  claim 17  wherein the forming step comprises forming a templated nanolaminate barrier film having a plurality of beads with concentric nanolaminate layers about each of the beads, wherein the concentric nanolaminate layers self-assemble about each of the beads. 
     
     
         21 . The method of  claim 17  wherein the forming step comprises forming a fused silica barrier film. 
     
     
         22 . The method of  claim 17  wherein the forming step comprises forming a polymer-based barrier film. 
     
     
         23 . The method of  claim 17  wherein the forming step comprises using a solution deposition process to form the encapsulant film. 
     
     
         24 . The method of  claim 17  wherein the forming step comprises using a dry powder process to deposit at least a portion of the encapsulant film.