Cell and module processing of semiconductor wafers for back-contacted solar photovoltaic module

摘要

The present invention relates to cost effective production methods of high efficiency silicon based back-contacted back-junction solar panels and solar panels thereof having a multiplicity of alternating rectangular emitter- and base regions on the back-side of each cell, each with rectangular metallic electric finger conductor above and running in parallel with the corresponding emitter- and base region, a first insulation layer in-between the wafer and finger conductors, and a second insulation layer in between the finger conductors and cell interconnections.

主权项

1. A method for manufacturing a back-contacted back-junction silicon solar cell module having a front side and a back side, the method comprising a set of module process steps A) to D) which are performed in successive order, the set of module process steps A) to D) comprising the steps of:
A) forming a multiplicity of semi-finished solar cells by repeatedly performing steps i) and ii) from a set of wafer process steps in successive order until the multiplicity is formed, wherein the steps i) and ii) of the set of wafer process steps are:
i) employing a crystalline silicon wafer having a back side and a front side and a layered stratified doped structure at least containing a back-side emitter layer and a base layer below the emitter layer, and where the wafer has a multiplicity of alternating rectangular emitter and base regions on the back side; andii) forming a texturing and depositing at least one surface passivation film on the front side of the wafer; B) laminating the multiplicity of semi-finished solar cells from module process step A) to a module front substrate, wherein each semi-finished solar cell is laid with their front-side facing the module front substrate in a rectangular tessellated-resembling pattern, and then performing steps iii) to vii) from the set of wafer process steps in successive order on the laminated multiplicity of semi-finished solar cells, wherein the steps iii) to vii) of the set of wafer process steps are:
iii) forming a back side surface passivation layer by depositing a continuous amorphous silicon layer covering the back side, in its entirety, of the wafer;iv) forming a first insulation layer onto the back side surface passivation layer with linear openings defining electric contact access areas running in parallel and located directly above each of the multiplicity of alternating rectangular emitter and base regions;v) forming rectangular metallic electric finger conductors, each of the rectangular metallic electric finger conductors being in parallel with and directly above each of the multiplicity of alternating rectangular emitter and base regions;vi) forming a second insulation layer onto each rectangular metallic electric finger conductor with a set of access openings at positions where electric contact with the rectangular metallic electric finger conductor is intended; andvii) forming a via contact in each access opening in the second insulation layer in electric contact with the rectangular metallic electric finger conductor lying below the access opening, and then C) forming functional solar cells of the semi-finished solar cells by forming a set of ribbon contacts on top of the second insulation layer with a set of access openings for interconnection of the semi-finished solar cells of the module, and D) laminating a back-side cover substrate onto the back-side of the module front substrate including the multiplicity of solar cells.