Source: Fraunhofer ISE
1 Silicon solar cell featured with Al-BSF
Aluminium back surface field (Al-BSF) by alloying the rear contact into the base resulting in n +pp+ structure allowed for a reduced recombination at the rear side.
2 Silicon solar cell featured with PERC
Substituting the fully contacted Al-BSF cell by the Passivated Emitter and Rear Cell (PERC) cell structure with local rear contacts makes better electrical and optical properties.
3 Silicon solar cell featured with TOPCon
Tunnel oxide passivating contact (TOPCon) consists in adding a thin tunnelling silicon dioxide (about 1.5 nm) and a doped polysilicon layer between the silicon substrate and the rear metal contact. In the case of an n-type substrate, a phosphorus-doped polysilicon layer is used as the rear contact structure.
4 Silicon solar cell featured with SHJ
Silicon heterojunction solar cells (SHJ) make use of passivating contacts based on a layer stack of intrinsic and doped amorphous silicon.
5 Silicon solar cell featured with IBC
Interdigitated back contact (IBC) solar cell with doping and contacts of both polarities on one side requires interdigitated (or striped) doping on the rear surface and only have contacts on the rear.
