High-efficiency heterojunction solar cell and manufacturing method thereof

The invention discloses a high-efficiency heterojunction solar cell and a manufacturing method thereof, and the cell comprises an N-type silicon wafer, a first intrinsic amorphous silicon layer, an N-type amorphous silicon layer, a transparent conductive layer, a metal grid line layer, a second intrinsic amorphous silicon layer, a second intrinsic amorphous silicon layer, a transparent conductive layer and a metal grid line layer, the second intrinsic amorphous silicon layer, the P-type microcrystalline silicon layer, the transparent conducting layer and the metal grid line layer are sequentially arranged on the back face of the silicon wafer. Wherein the P-type microcrystalline silicon layer is formed by sequentially depositing gradually-changed boron-doped gas concentration gradients from low to high. The low doping concentration adopted in the initial film forming stage of the P-type microcrystalline silicon layer is beneficial to growth of a microcrystalline silicon film, so that the crystallization rate