Selective doping passivation contact structure and preparation method and application thereof

The invention discloses a selective doping passivation contact structure and a preparation method and application thereof. The preparation method comprises the steps that a tunneling silicon oxide layer, an in-situ doping amorphous silicon layer and a mask layer are sequentially arranged on the back surface of a silicon wafer; grooving a part, corresponding to the metal contact area of the silicon wafer, on the mask layer, and removing the mask layer at the part; a phosphorus source is introduced, phosphorus diffusion treatment is carried out, and in the phosphorus diffusion treatment, the in-situ doped amorphous silicon layer is converted into a phosphorus doped polycrystalline silicon layer; according to the method, a passivation contact structure with a heavily doped metal contact area and a lightly doped non-metal contact area can be prepared, and properties such as lower surface recombination, lower metal recombination and lower interface contact resistance can be realized; particularly, the method is si