The present application provides a solar cell including a crystalline silicon substrate. A doped silicon oxide layer (131), a doped polycrystalline silicon film (132), and a back aluminum oxide film (133) are sequentially disposed on a back side of the crystalline silicon substrate. The doped polycrystalline silicon film (133) has a thickness of 5 nm to 50 nm. A back metal electrode (150) is also provided on the back side of the crystalline silicon substrate. The back metal electrode (150) passes through the back aluminum oxide film (133) to be in contact with the doped polycrystalline silicon film (132).