STRUCTURES AND METHODS OF FORMATION OF CONTIGUOUS AND NON-CONTIGUOUS BASE REGIONS FOR HIGH EFFICIENCY BACK-CONTACT SOLAR CELLS

1 . A back contact, back-junction crystalline semiconductor solar cell, comprising:

a crystalline semiconductor substrate, said substrate comprising a light receiving passivated frontside surface and a passivated backside surface comprising patterned interdigitated doped emitter and base regions;

a patterned electrical insulator layer on said backside surface, said patterned electrical insulator layer comprising a doped layer proximate said backside surface and an undoped capping layer on said doped layer; and

a contact metallization pattern comprising emitter metallization electrodes contacting said emitter regions and non-nested base metallization electrodes contacting said base regions, said non-nested base metallization electrodes go beyond said base regions to overlap at least a portion of said patterned insulator without causing electrical shunts in said solar cell.

2 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said emitter and base metallization electrodes comprise aluminum.

3 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said emitter and base metallization electrodes comprise aluminum silicon.

4 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said emitter and base metallization electrodes have an interdigitated pattern.

5 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said solar cell uses a second patterned metallization layer separated from said contact metallization pattern by an electrically insulating backplane.

6 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said patterned electrical insulator layer comprises a combination of at least a doped glass layer and an undoped glass layer.

7 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said patterned electrical insulator layer comprises a combination of a first layer of borosilicate glass and a second layer of phosphorous silicate glass.

8 . The back contact crystalline semiconductor solar cell of claim 1 , wherein said patterned electrical insulator layer comprises a combination of a first layer of borosilicate glass, a second layer of borosilicate glass, and a phosphorous silicate glass.

9 . A back contact, back-junction crystalline semiconductor solar cell, comprising:

a crystalline semiconductor substrate, said substrate comprising a light receiving passivated frontside surface and a passivated backside surface comprising doped emitter and non-contiguous discrete base regions;

a patterned electrical insulator layer on said backside surface, said patterned electrical insulator layer comprising a doped layer proximate said backside surface and an undoped capping layer on said doped layer; and

a contact metallization pattern comprising emitter metallization electrodes contacting said emitter regions and non-nested base metallization electrodes contacting said base regions, said non-nested base metallization electrodes go beyond said base regions to overlap at least a portion of said patterned insulator without causing electrical shunts in said solar cell.

10 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said emitter and base metallization electrodes comprise aluminum.

11 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said emitter and base metallization electrodes comprise aluminum silicon.

12 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said emitter and base metallization electrodes have an interdigitated pattern.

13 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said solar cell uses a second patterned metallization layer separated from said contact metallization pattern by an electrically insulating backplane.

14 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said patterned electrical insulator layer comprises a combination of at least a doped glass layer and an undoped glass layer.

15 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said patterned electrical insulator layer comprises a combination of a first layer of borosilicate glass and a second layer of phosphorous silicate glass.

16 . The back contact crystalline semiconductor solar cell of claim 9 , wherein said patterned electrical insulator layer comprises a combination of a first layer of borosilicate glass, a second layer of borosilicate glass, and a phosphorous silicate glass.

17 . A method for forming a back-contact, back-junction crystalline semiconductor solar cell, comprising:

forming patterned interdigitated doped emitter and base regions on a backside surface of a crystalline semiconductor substrate;

forming patterned electrically insulating layer stack comprising a combination of at least a doped layer and an undoped capping layer on said patterned doped emitter and base regions;

forming a contact metallization pattern comprising emitter metallization electrodes contacting said emitter regions and non-nested base metallization electrodes contacting said base regions, said non-nested base metallization electrodes go beyond said base regions to overlap at least a portion of said patterned insulator without causing electrical shunts in said solar cell.

18 . The method for forming a back contact, back-junction solar cell of claim 17 , wherein said electrically insulating layer stack is formed according to a chemical vapor deposition process.

19 . The method for forming a back contact, back-junction solar cell of claim 17 , wherein said electrically insulating layer stack is formed using an atmospheric pressure chemical vapor deposition process.

20 . The method for forming a back contact, back-junction solar cell of claim 17 , wherein said electrically insulating layer comprises a combination of at least a doped oxide layer and an undoped oxide layer.