The
conductive paste provided by this invention comprises a conductive
metal, lead-free glass
powder, and an organic binder. The conductive
metal and the lead-free glass
powder constitute the total solids content, wherein the content of the conductive
metal in the total solids content is 75-99.8 wt%, and the content of the lead-free glass
powder is 0.2-25 wt%. The lead-free glass powder is a Te-Bi
oxide system, which includes
tellurium oxide and
bismuth oxide.
Tellurium oxide, as a glass network former, mainly determines the
softening point and fluidity of the glass, effectively reducing the
melting point and imparting good fluidity.
Bismuth oxide, as a network modifier, can regulate the
chemical activity of the glass, allowing it to moderately corrode the
passivation layer during
sintering and promoting the formation of silver-
silicon ohmic contacts. Adjusting the ratio of the two within this range allows for precise matching of the
sintering temperature curves of different
crystalline silicon solar cells, broadening the
process window for lead-free glass. Furthermore, this invention also provides a method for preparing the
conductive paste.