Thermal Repair of Incomplete Back Contact Insulation (P1) in Cu(In,Ga)Se2 Photovoltaic Thin-Film Modules

We investigate the repair of interruptions in the back contact (P1) scribing line between two Mo back electrodes by thermally induced fractures. The fractures occur during Cu(In,Ga)Se2 (CIGS) absorber co-evaporation, as it is applied in CIGS thin-film module manufacturing and can effectively repair line interruptions of up to about 70 μm. Additionally, we present that a thermal treatment after P1 laser scribing and before CIGS co-evaporation can repair even interruptions of up to 1 mm. The fractures which are required for insulation are only of approximately 4 μm width which indicates the potential for further reduction of the interconnection width in CIGS modules and therefore improvement of the electrical module efficiency.