Bifacial crystalline silicon solar panel with reflector

Abstract

Bifacial crystalline solar cells and associated solar panel systems are provided. The cells include a p-type crystalline silicon layer and a barrier layer. The panels include at least two rows of cells. The cells in each row are connected to one another in series. The rows are connected in parallel. A reflector is used to reflect light towards the underside of the panel. A long axis of the reflector is arranged to be parallel to the rows of cells.

What is claimed is: 
     
         1 . A bifacial solar cell ( 110 ) comprising:
 (a) an n-type semiconductor layer ( 32 );   (b) a plurality of first metal conductivity lines ( 24 ) coupled to a first side of the n-type semiconductor layer ( 32 );
 wherein at least some of the first metal conductivity lines ( 24 ) are in electrical communication with the n-type semiconductor layer ( 32 ); 
   (c) a p-type crystalline silicon layer ( 36 ) coupled to a second side of the n-type semiconductor layer ( 32 );   (d) a barrier layer ( 40 ) coupled to the p-type crystalline silicon layer ( 36 ), and located opposite the n-type semiconductor layer ( 32 );
 wherein the barrier layer ( 40 ) comprises at least one of:
 oxides of vanadium, oxides of molybdenum, nitrides of aluminum, tungsten nickel oxide, and boron doped diamond; 
 
   (e) a transparent conductive layer ( 44 ) coupled to the barrier layer ( 40 ), and located opposite the p-type crystalline silicon layer ( 36 );   (f) a plurality of second metal conductivity lines ( 48 ) coupled to the transparent conductive layer  44 , and located opposite the barrier layer ( 40 );
 wherein at least some of the second metal conductivity lines ( 48 ) are in electrical communication with the transparent conductive layer ( 44 ). 
   
     
     
         2 . The bifacial solar cell ( 110 ) of  claim 1 , wherein the barrier layer is an oxide of vanadium. 
     
     
         3 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the composition of the oxide of vanadium is described by the empirical formula V x O y , and wherein 0.130≦x/(x+y)≦0.60. 
     
     
         4 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the composition of the oxide of vanadium is described by the empirical formula V 2 O 5 . 
     
     
         5 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the thickness of the barrier layer is at least 1.0 nanometers. 
     
     
         6 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the thickness of the barrier layer is at least 2.0 nanometers. 
     
     
         7 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the thickness of the barrier layer is not greater than 10.0 nanometers. 
     
     
         8 . The bifacial solar cell ( 110 ) of  claim 2 , wherein the thickness of the barrier layer is not greater than 6.0 nanometers. 
     
     
         9 . The bifacial solar cell ( 110 ) of  claim 1  comprising:
 a passivation layer ( 28 ),
 wherein the passivation layer ( 28 ) is coupled to the first side of the n-type semiconductor layer ( 32 ), and disposed between the plurality of first metal conductivity lines ( 24 ). 
 
 
     
     
         10 . A photovoltaic system comprising:
 (i) a solar panel ( 100 ) having solar cells, the solar panel ( 100 ) comprising:
 (a) a first row ( 112 ) of solar cells electrically connected in series;
 wherein the first row ( 112 ) has a first long axis ( 113 ); 
 
 (b) a second row ( 114 ) of solar cells electrically connected in series;
 wherein the second row ( 114 ) is adjacent to the first row ( 112 ); 
 wherein the second row ( 114 ) has a second long axis ( 115 ); 
 wherein the second long axis ( 115 ) is coincidental to the first long axis ( 113 ); 
 
 wherein the first row ( 112 ) is electrically connected to the second row ( 114 ) in parallel; 
 wherein at least some of the solar cells are bifacial solar cells ( 110 ); and 
   (ii) at least one reflector ( 120 ) located proximal the solar panel ( 100 );
 wherein the reflector ( 120 ) includes a reflective surface ( 130 ) facing the solar panel ( 100 ); 
 wherein the reflective surface ( 130 ) has a third long axis ( 132 ); and 
 wherein the third long axis ( 132 ) is coincidental to the first and second long axes ( 113 ,  115 ). 
   
     
     
         11 . The photovoltaic system of  claim 10 , wherein the third long axis ( 132 ) forms an angle of from 5° to negative 5° to the first and second long axes ( 113 ,  115 ). 
     
     
         12 . The photovoltaic system of  claim 10 , wherein the reflective surface ( 130 ) comprises at least one of aluminum and silver. 
     
     
         13 . The photovoltaic system of  claim 10 , wherein at least a portion of the reflective surface ( 130 ) is white. 
     
     
         14 . The photovoltaic system of  claim 10 , wherein the reflective surface ( 130 ) has a compound-parabolic-shaped profile. 
     
     
         15 . The photovoltaic system of  claim 10 , wherein the reflective surface ( 130 ) has a semicircular-shaped profile. 
     
     
         16 . The photovoltaic system of  claim 10 , wherein the reflective surface ( 130 ) has a profile comprising planar surfaces. 
     
     
         17 . The photovoltaic system of  claim 10  wherein the bifacial solar cells ( 110 ) comprise:
 (I) an n-type semiconductor layer ( 32 ); 
 (II) a plurality of first metal conductivity lines ( 24 ) coupled to a first side of the n-type semiconductor layer ( 32 );
 wherein at least some of the first metal conductivity lines ( 24 ) are in electrical communication with the n-type semiconductor layer ( 32 ); 
 
 (III) a p-type crystalline silicon layer ( 36 ) coupled to a second side of the n-type semiconductor layer ( 32 ); 
 (IV) a barrier layer ( 40 ) coupled to the p-type crystalline silicon layer ( 36 ), and located opposite the n-type semiconductor layer ( 32 );
 wherein the barrier layer ( 40 ) comprises at least one of:
 oxides of vanadium, oxides of molybdenum, nitrides of aluminum, tungsten nickel oxide, and boron doped diamond; 
 
 
 (V) a transparent conductive layer ( 44 ) coupled to the barrier layer ( 40 ), and located opposite the p-type crystalline silicon layer ( 36 ). 
 (VI) a plurality of second metal conductivity lines ( 48 ) coupled to the transparent conductive layer ( 44 ), and located opposite the barrier layer ( 40 );
 wherein at least some of the second metal conductivity lines ( 48 ) are in electrical communication with the transparent conductive layer ( 44 ). 
 
 
     
     
         18 . The photovoltaic system of  claim 17  wherein the bifacial solar cells ( 110 ) comprise:
 a passivation layer ( 28 );
 wherein the passivation layer ( 28 ) is coupled to the first side of the n-type semiconductor layer ( 32 ), and disposed between the plurality of first metal conductivity lines ( 24 ). 
 
 
     
     
         19 . The photovoltaic system of  claim 17  comprising:
 a first transparent protective layer ( 20 ); and 
 a second transparent protective layer ( 52 ); 
 wherein the solar cells are disposed between the first transparent protective layer ( 20 ) and the second transparent protective layer ( 52 ). 
 
     
     
         20 . The photovoltaic system of  claim 19 , wherein the first transparent protective layer ( 20 ) is coupled to the plurality of first metal conductivity lines ( 24 ) via a first lamination layer ( 22 ); and wherein the second transparent protective layer ( 52 ) is coupled to the plurality of second metal conductivity lines via a second lamination layer ( 50 ).