Aging behaviour of laser welded Al-interconnections in crystalline silicon modules

We investigate the artificial aging of PV modules interconnected with the aluminum-based mechanical and electrical laser interconnection (AMELI) process. AMELI forms a laser welded connection between the Al-metallization on the rear side of the solar cell and an Al-layer on an interconnector substrate. AMELI avoids soldering, conductive adhesives, and Ag-pastes. We investigate glass and encapsulant films as possible interconnector substrates that carry an Al-film. Modules processed with high temperature-deposited aluminum on the cells and an encapsulant as interconnector substrate do not degrade during 200 humidity-freeze cycles. The conversion efficiency η, the fill factor FF, the open circuit voltage Voc, and the short circuit current Isc are unaffected by the artificial aging within an accuracy of 1%.

► The Al-laser welding process is suitable for module integration of BJBC solar cells. ► Loss- and damage-free interconnection of PVD Al-metalized solar cells. ► Interconnection of the cells without soldering, Ag-pastes, or conductive adhesives. ► Fabricated modules are stable under 200 humidity-freeze cycles.