Monolithic bypass-diode and solar-cell string assembly

Abstract

An apparatus and method for making a solar cell with an integrated bypass diode. The method comprises the steps of depositing a second layer having a first type of dopant on a first layer having an opposite type of dopant to the first type of dopant to form a solar cell, depositing a third layer having the first type of dopant on the second layer, depositing a fourth layer having the opposite type of dopant on the third layer, the third layer and fourth layer forming a bypass diode, selectively etching the third layer and the fourth layer to expose the second layer and the third layer, and applying contacts to the fourth layer, third layer, and the first layer to allow electrical connections to the assembly. The apparatus comprises a first layer having a first type of dopant, a second layer having a second type of dopant opposite to the first type of dopant, wherein the first layer and the second layer form a solar cell, a third layer, coupled to the second layer, and a fourth layer, coupled to the third layer, the third layer and the fourth layer forming a bypass diode.

What is claimed is:  
     
         1 . A solar cell assembly, comprising: 
 a first layer having a first type of dopant;    a second layer having a second type of dopant opposite to the first type of dopant, the second layer coupled to the first layer, the first layer and the second layer forming a solar cell;    a third layer, coupled to the second layer; and    a fourth layer, coupled to the third layer, the third layer and fourth layer forming a bypass diode.    
     
     
         2 . The assembly of  claim 1 , wherein the bypass diode of a first assembly is connected in anti-parallel with the solar cell of a second assembly.  
     
     
         3 . The assembly of  claim 1 , further comprising a fifth layer disposed between the third layer and the fourth layer, wherein the fourth layer and the fifth layer form a bypass diode.  
     
     
         4 . The assembly of  claim 3 , wherein the bypass diode of a first assembly is connected with the solar cell of a second assembly in an anti-parallel configuration.  
     
     
         5 . An solar cell assembly with an integrated bypass diode, comprising: 
 a solar cell, comprising a first layer having a first dopant type and a second layer having a dopant type opposite to the first dopant type;    a tunnel junction layer, coupled to the solar cell; and    a bypass diode, coupled to the tunnel junction layer, comprising a third layer having the first dopant type and a fourth layer having the opposite dopant type, the fourth layer being electrically coupled to the first layer for creating an anti-parallel configuration of the solar cell and the bypass diode therein.    
     
     
         6 . The solar cell assembly of  claim 5 , further comprising a second solar cell disposed between the solar cell and the tunnel junction layer.  
     
     
         7 . A method for making a solar cell and an integrated bypass diode assembly, comprising the steps of: 
 depositing a first layer having a first type of dopant on a second layer having an opposite type of dopant to the first type of dopant to form a solar cell;    depositing a third layer having the first type of dopant on the first layer;    depositing a fourth layer having the opposite type of dopant on the third layer, the third layer and the fourth layer forming a bypass diode;    selectively etching the third layer and the fourth layer to expose the first layer and the third layer; and    applying contacts to the second layer, the third layer, and the fourth layer to allow electrical connections to the assembly.    
     
     
         8 . The method of  claim 7 , further comprising the steps of: 
 connecting the contact on the substrate of a first assembly to the contact on the second layer of a second assembly; and    connecting the contact on the second layer of the first assembly to the contact on the third layer of the second assembly for connecting the solar cell of the first assembly to the bypass diode of the second assembly in an anti-parallel configuration.    
     
     
         9 . The method of  claim 7 , further comprising the step of depositing a fourth layer disposed between the second layer and third layer, wherein the third layer and the fourth layer form a bypass diode.  
     
     
         10 . The method of  claim 7 , further comprising the step of depositing a fourth layer and a fifth layer disposed between the substrate and the first layer, wherein the substrate and the fourth layer form a first solar cell and the fifth layer and the first layer form a second solar cell.  
     
     
         11 . A solar cell assembly, comprising: 
 a first layer having a first type of dopant;    a second layer having a second type of dopant opposite to the first type of dopant, the second layer coupled to the first layer, the first layer and the second layer forming a first solar cell junction;    a third layer, coupled to the second layer;    a fourth layer, coupled to the third layer, the third layer and fourth layer forming a second solar cell junction, the first solar cell junction and the second solar cell junction forming a solar cell;    a fifth layer, coupled to the fourth layer; and    a sixth layer, coupled to the fifth layer, the fifth layer and the sixth layer forming a bypass diode.    
     
     
         12 . The assembly of  claim 11 , wherein the bypass diode of a first assembly is connected in anti-parallel with the solar cell of a second assembly.  
     
     
         13 . A solar cell assembly, comprising: 
 a first layer having a first type of dopant;    a second layer having a second type of dopant opposite to the first type of dopant, the second layer coupled to the first layer, the first layer and the second layer forming a first solar cell junction;    a third layer, coupled to the second layer;    a fourth layer, coupled to the third layer, the third layer and fourth layer forming a second solar cell junction;    a fifth layer, coupled to the fourth layer;    a sixth layer, coupled to the fifth layer, the fifth layer and the sixth layer forming a third solar cell junction, the first solar cell junction, the second solar cell junction, and the third solar cell junction forming a solar cell;    a seventh layer, coupled to the sixth layer; and    an eighth layer, coupled to the seventh layer, the seventh layer and the eighth layer forming a bypass diode.    
     
     
         14 . The assembly of  claim 13 , wherein the bypass diode of a first assembly is connected in anti-parallel with the solar cell of a second assembly.