A solar cell, comprising: a substrate having a first surface and a second surface opposite to each other; a first passivation stack disposed on the first surface and including a first oxygen-rich dielectric layer, a first silicon-rich dielectric layer, a second oxygen-rich dielectric layer, and a second silicon-rich dielectric layer that are sequentially disposed in this order in a direction away from the first surface, wherein an atomic fraction of oxygen in the first oxygen-rich dielectric layer is less than an atomic fraction of oxygen in the second oxygen-rich dielectric layer, wherein the atomic fraction of oxygen in the first oxygen-rich dielectric layer is in a range of 40% to 70%, the first silicon-rich dielectric layer includes oxygen atoms in which the atomic fraction of oxygen is greater than 0% and less than or equal to 10%, the atomic fraction of oxygen in the second oxygen-rich dielectric layer is in a range of 50% to 80%, and the second silicon-rich dielectric layer includes oxygen atoms in which the atomic fraction of oxygen is greater than 0% and less than or equal to 10%; wherein a material of the first oxygen-rich dielectric layer includes at least one of aluminum oxide, silicon oxide, silicon oxynitride, gallium oxide, titanium oxide, and hafnium oxide, and a material of the second oxygen-rich dielectric layer includes at least one of silicon oxide and silicon oxynitride; a tunneling oxide layer disposed on the second surface; a doped silicon layer disposed on a surface of the tunneling oxide layer; and a second passivation layer disposed on a surface of the doped silicon layer. a substrate having a first surface and a second surface opposite to each other; a first passivation stack disposed on the first surface and including a first oxygen-rich dielectric layer, a first silicon-rich dielectric layer, a second oxygen-rich dielectric layer, and a second silicon-rich dielectric layer that are sequentially disposed in this order in a direction away from the first surface, wherein an atomic fraction of oxygen in the first oxygen-rich dielectric layer is less than an atomic fraction of oxygen in the second oxygen-rich dielectric layer, wherein the atomic fraction of oxygen in the first oxygen-rich dielectric layer is in a range of 40% to 70%, the first silicon-rich dielectric layer includes oxygen atoms in which the atomic fraction of oxygen is greater than 0% and less than or equal to 10%, the atomic fraction of oxygen in the second oxygen-rich dielectric layer is in a range of 50% to 80%, and the second silicon-rich dielectric layer includes oxygen atoms in which the atomic fraction of oxygen is greater than 0% and less than or equal to 10%; wherein a material of the first oxygen-rich dielectric layer includes at least one of aluminum oxide, silicon oxide, silicon oxynitride, gallium oxide, titanium oxide, and hafnium oxide, and a material of the second oxygen-rich dielectric layer includes at least one of silicon oxide and silicon oxynitride; a tunneling oxide layer disposed on the second surface; a doped silicon layer disposed on a surface of the tunneling oxide layer; and a second passivation layer disposed on a surface of the doped silicon layer.