Backside emitter solar cell structure having a heterojunction and method and device for producing the same
A backside emitter solar cell structure having a heterojunction, and a method and a device for producing the same. A backside intrinsic layer is first formed on the back side of the substrate, then a frontside intrinsic layer and a frontside doping layer are formed on the front side of the substrate, and finally a backside doping layer is formed on the back side of the substrate.
1. A device for producing a backside emitter solar cell structure with a heterojunction,
wherein the solar cell structure includes:
an absorber made of a crystalline semiconductor substrate having a doping of a first conductivity type;
at least one frontside intrinsic layer formed on a front side of the absorber and made of an intrinsic, amorphous semiconductor material;
at least one backside intrinsic layer formed on a back side of the absorber and made of an intrinsic, amorphous semiconductor material;
at least one frontside doping layer formed on the at least one frontside intrinsic layer from an amorphous semiconductor material having a doping of the first conductivity type which is higher than the doping of the absorber;
an emitter of at least one backside doping layer formed on the at least one backside intrinsic layer and made of an amorphous semiconductor material having a doping of a second conductivity type, which is opposite to the first conductivity type;
at least one electrically conductive, transparent frontside conduction layer formed on the at least one frontside doping layer;
at least one electrically conductive, transparent backside conduction layer formed on the at least one backside doping layer;
a frontside contact formed on the at least one frontside conduction layer; and
a backside contact formed on the at least one backside conduction layer; and
the device for producing the backside emitter solar cell structure comprising:
no more than three layer deposition strands for producing the at least one frontside intrinsic layer on the front side of the semiconductor substrate, the at least one backside intrinsic layer on the back side of the semiconductor substrate, the at least one frontside doping layer on the at least one frontside intrinsic layer, and the at least one backside doping layer on the at least one backside intrinsic layer;
said layer deposition strands including a first layer deposition strand having at least one layer deposition reactor for producing the at least one backside intrinsic layer on the back side of the semiconductor substrate;
said layer deposition strands including a second layer deposition strand having at least one layer deposition reactor for producing the at least one frontside intrinsic layer on the front side of the semiconductor substrate and for producing the at least one frontside doping layer on the at least one frontside intrinsic layer; and
said layer deposition strands including a third layer deposition strand having at least one layer deposition reactor for producing the at least one backside doping layer on the at least one backside intrinsic layer; and
at least one substrate transport and turning system between said first and second layer deposition strands and between said second and third layer deposition strands.
2. The device according to claim 1 , wherein:
said first layer deposition strand has a backside intrinsic layer deposition reactor for producing the at least one backside intrinsic layer on the back side of the semiconductor substrate;
the second layer deposition strand has a single frontside layer deposition reactor for producing the at least one frontside intrinsic layer on the frontside of the semiconductor substrate and the at least one frontside doping layer on the at least one frontside intrinsic layer;
the third layer deposition strand has a backside doping layer deposition reactor for producing the at least one backside doping layer on the at least one backside intrinsic layer; and
the at least one substrate transport and turning system is disposed upstream of said frontside layer deposition reactor before or in said second layer deposition strand.