Back aluminium diffused N type solar cell and manufacturing method of back electrode

The invention relates to a back aluminium diffused N type solar cell and manufacturing method of back electrode. The solar cell has the structure that a silver metal grid line positive electrode (1), a silicon nitride antireflection coating (2), a phosphor diffusion layer (3) arranged on the front of a silicon slice, a N type single crystal silicon slice (4), a silver-aluminium back electrode (6) arranged on the back of the silicon slice and a back aluminium P type diffusion layer (7) arranged on the back of the silicon slice are sequentially arranged from front to back; and the solar cell is characterized in that the back of the N type single crystal slice (4) arranged between the back of the N type single crystal silicon slice (4) and the silver-aluminium back electrode (6) is provided with a P type isolating layer (5). The invention can cause N type cell to be produced without modifying conventional P type solar production line and solves one of key problems of collineation production of N type cell and P type cell.