Individually encapsulated solar cells and solar cell strings

Abstract

Methods and devices are provided for improved environmental protection for photovoltaic devices and assemblies. In one embodiment, the device comprises of an individually encapsulated solar cell, wherein the encapsulated solar cell includes at least one protective layer coupled to at least one surface of the solar cell. The protective layer has a chemical composition that prevents moisture from entering the solar cell and wherein light passes through the protective layer to reach an absorber layer in the solar cell.

1 . A flexible solar panel comprising:
 a plurality of solar cells;   wherein the solar cells are covered on at least one surface by a multi-layer film having one or more layers of a first material and one or more layers of a second material, wherein the multi-layer film contains randomly located pinholes or gaps at interfaces between layers that define long tortuous pathways that slow water penetration through the multi-layer film;   wherein a plurality of particles each sized between about 1 nm to about 10 microns which are contained in the multi-layer film to block tortuous pathways through the film, wherein at least a portion of each of the particles is in contact with one of the layers of the first material or one of the layers of the second material and wherein substantially all of the tortuous pathways are blocked by-at least one of the particles.   
     
     
         2 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises at least one material selected from the group consisting of: silica, alumina, aluminosilicates, diamond-like films, borosilicates, silicon nitride, aluminophosphosilicates, aluminophosphates Niobium oxide (Nb 2 O 5 ), Niobium nitride (NbN), Zirconium Oxide (ZrO 2 ), Zirconium Nitride (ZrN), Hafnium Oxide (HfO 2 ), Hafnium nitride (HfN), Zinc oxide (ZnO), Yttrium oxide (Y 2 O 3 ), Cerium Oxide (CeO 2 ), Scandium Oxide (Sc 2 O 3 ), Erbium oxide (Er 2 O 3 ), Tantalum oxide (Ta 2 O 5 ), Tantalum nitride (TaNx), Vanadium oxide (V 2 O 5 ), Indium Oxide (In 2 O 3 ), Aluminum nitride (AlN), Titanium Nitride (TiN), Molybdenum nitride (MoN), Gallium nitride (GaN), Lanthanum oxide (La 2 O 3 ), Zinc Sulfide (ZnS), Tin oxide (SnO 2 ), strontium sulfide (SrS), calcium sulfide (CaS), lead sulfide (PbS), indium tin oxide (ITO), tungsten oxide, calcium/titanium oxide, and/or combinations thereof. 
     
     
         3 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises of a nanolaminate comprised of at least one material combination selected from the group consisting of: hafnium oxide/tantalum oxide, titanium oxide/tantalum oxide, titania/alumina, zinc sulfide/alumina, ATO, AlTiO, and/or combinations thereof. 
     
     
         4 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises of a first layer of a first inorganic material and a second layer of a second inorganic material. hafnium oxide/tantalum oxide, titanium oxide/tantalum oxide, titania/alumina, zinc sulfide/alumina, ATO, or AlTiO 
     
     
         5 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises of a layer of silica layer and a layer of alumina. 
     
     
         6 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises a plurality of fused inorganic particles. 
     
     
         7 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises a plurality of fused silica particles. 
     
     
         8 . The flexible solar panel of  claim 1  wherein the multi-layer film is a layer deposited by atomic layer deposition. 
     
     
         9 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises of a plurality of layers deposited by atomic layer deposition. 
     
     
         10 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises of a silico-acrylic composition. 
     
     
         11 . The flexible solar panel of  claim 1  wherein the multi-layer film comprises:
 a plurality of layers of an inorganic material; and 
 a plurality of layers of an organic material wherein the layers of organic material alternate with the layers of inorganic material; 
 wherein adjacent layers of the organic material and the inorganic material are covalently bonded layers characterized by covalent bonds that couple adjacent layers together. 
 
     
     
         12 . The flexible solar panel of  claim 11  wherein each of the layers of inorganic material has a thickness of about 0.1 nm to about 1 nm; about 1 to about 10 nm; or about 1 nm to about 100 nm. 
     
     
         13 . The flexible solar panel of  claim 1  wherein the multi-layer film has a water vapor transmission rate (WVTR) sufficiently low so that there is substantially no loss in solar cell conversion efficiency when the cell is exposed for 1000 hours at 85° C. and 85% relative humidity. 
     
     
         14 . The flexible solar panel of  claim 1  wherein the multi-layer film has a WVTR such that the conversion efficiency of a cell with the multi-layer film has a conversion efficiency at least 25% better than an unprotected cell after both are exposed for 1000 hours at 85° C. and 85% relative humidity. 
     
     
         15 . The flexible solar panel of  claim 1  wherein the multi-layer film layer has a WVTR such that the conversion efficiency of a cell with the multi-layer film has a conversion efficiency at least 50% better than an unprotected cell after both are exposed for 1000 hours at 85° C. and 85% relative humidity. 
     
     
         16 . The flexible solar panel of  claim 1  further comprising an anti-reflective layer above the multi-layer film. 
     
     
         17 . The flexible solar panel of  claim 1  wherein the multi-layer film has anti-reflective qualities. 
     
     
         18 . The flexible solar panel of  claim 1  wherein the particles are comprised of a material selected from the group consisting of: silica, glass, or other transparent inorganic materials. 
     
     
         19 . The flexible solar panel of  claim 1  wherein the particles have a shape selected from the group consisting of: spherical, platelet, or flake. 
     
     
         20 . The flexible solar panel of  claim 1  wherein the particles are sized to be within 5-10% of each other.