Crystalline silicon solar cells at low cost and back silver paste prepared using unleaded

Silver materials and low-cost method for producing a crystalline silicon solar cell with a back lead-free. Components and weight percents of the lead-free conductive silver paste is as follows: 40 to 55% silver; lead-free glass binder is 5 to 15%; 30 to 55% organic binder; disintegration aids 0 to 1.0%; wherein said silver powder is from 2 to 10 microns average particle diameter, specific surface area of ​​1.8 ~ 2.4m2 / g of silver flake micro; the organic binder by several different decomposition temperature of the organic resin with a different evaporation rate organic solvent. The present invention is made of silver conductive paste back, moderate viscosity, a dense electrode layer is formed, good weldability, high conversion efficiency.