Environmentally-friendly, Pb-free Cu front electrode for Si-based solar cell applications

According to our investigation, a model of the reaction mechanisms in the double glass system of Cu paste in each sintering stage is proposed. And we have shown that Ohmic contact and good sheet resistance for the Cu front electrode with Pb-free could both be obtained by applying the newly-invented Cu paste and two steps of firing process. The lowest sheet resistance and contact resistance for such a Cu front electrode measured are 0.090 Ω/□ and 0.0040 Ω/□, respectively.