The invention relates to a selective emitter junction and tunneling 
oxide efficient N-type battery preparation method. The method comprises the steps of: performing texturing after removing a damaged layer of a 
silicon wafer, forming a 
boron-doped P+ emitter junction on the front surface, forming a local heavily doped region by means of 
laser treatment, growing an ultra-thin tunneling 
oxide layer and a 
phosphorus-doped 
silicon thin film on the back surface of the 
silicon wafer, depositing an 
aluminium oxide layer on the surface of the P+ emitter junction, growing a hydrogenated 
silicon nitride passivation antireflection layer on the front surface of the silicon 
wafer, and finally printing an Ag / Al 
slurry on the front surface of the silicon wafer. According to the selective emitter junction and tunneling oxide efficient N-type battery preparation method, a metalized 
ohmic contact structure of Ag or Al is formed on the back surface through metallization, low-temperature annealing is carried out by means of a 
drying oven, and the contact performance of electrodes is improved. Compared with the prior art, the selective emitter junction and tunneling oxide efficient N-type battery preparation method adopts the selective emitter junction on the front surface as well as the ultra-thin tunneling oxide layer (<4 nm) and the 
phosphorus-doped 
silicon thin film on the back surface, thus can significantly reduce the 
metal-
semiconductor surface recombination on the front surface and the back surface, and has the most obvious 
advantage of being capable of greatly increasing 
electrical performance parameters on the basis of being compatible with the traditional battery manufacturing process.