Study on chemical bonding states at electrode-silicon interface fabricated with fire-through control paste

We investigated the interface phenomena between the electrode by a low fire-through electrode paste and the silicon substrate in a crystalline silicon solar cell. Oblique polishing was used to evaluate the chemical bonding states in the depth direction. From the evaluation by X-ray photoelectron spectroscopy (XPS) and the hard X-ray photoelectron spectroscopy (HAXPES), we found changes in the chemical bonding states of Ag 3d, Si 2p, O 1s, and N 1s at the electrode-silicon interface. In addition, it was possible to confirm the reduction of Ag induced by the heat treatment at the interface. Thus, it became possible to evaluate the chemical bonding states at the interface between the electrode and the silicon substrate by adapting oblique polishing and XPS measurement.