Recombination and Resistive Losses of Transferred Foil Contacts for Silicon Heterojunction Solar Cells

Abstract

Silicon heterojunction (SHJ) solar cells have been studied extensively due to their potential to reach high energy conversion efficiencies. However, one of the limiting factors for this technology is the metallization, which uses low‐curing‐temperature silver pastes that result in fingers with higher bulk resistivity. Herein, a simple approach to fabricate the SHJ solar cell contacts is demonstrated with commercially available low‐cost silver (Ag) electrically conductive adhesive (ECA) pastes and aluminium (Al) foils. This technique can result in a transparent conductive oxide (TCO)‐free cell structure and has the potential to combine cell metallization and interconnection. Recombination and resistive loss analyses are performed on the fabricated test samples. A dark saturation current density at the contact (J0c) of 3.05 fA cm−2 for test samples before annealing is reported. The analysis of the experimental and simulated photoluminescence (PL) images shows negligible added recombination. The contact resistivity (ρc) value is 49.3 mΩ cm2 after annealing which can be optimized by specialized ECA pastes.