Characteristics of Pb-based glass powders prepared by spray pyrolysis as inorganic additive of Al paste for solar cell

Al conducting films are formed from the Al pastes with various amounts of glass powders. Pb-based glass powders with submicron size and spherical shape prepared by spray pyrolysis are used. The Al films formed from the Al pastes with high amount of glass powders have good adhesion properties with Si wafers. The optimum glass contents showing the minimum sheet resistance of the Al film changed according to the firing temperatures. The optimum glass contents are 7, 5 and 3 wt% of Al content at firing temperatures of 700, 800 and 900 °C, respectively. The minimum sheet resistance of the Al film with thickness of 31.4 μm is 9.5 mΩ/sq.