Preparation method of heterojunction solar cell and heterojunction solar cell

The invention discloses a preparation method of a heterojunction solar cell and the heterojunction solar cell. The method includes the steps of providing a substrate, and providing intrinsic layers at both sides of the substrate to form a first structure of the heterojunction solar cell; subjecting the intrinsic layer interfaces of the first structure to deoxidation process via plasma, and providing doped layers at both sides of the processed first structure to form a second structure; forming transparent conductive layers at both sides of the second structure to serve as a front electrode and a rear electrode, or forming a transparent conductive layer at one side of the second structure to serve as the front electrode and a composite rear electrode of transparent conductive oxide and a metal composite layer at the other side of the second structure. Photoelectric conversion efficiency of the heterojunction solar cell is thus improved.