A solar cell includes a silicon substrate, a passivation layer, a first protection layer, a second protection layer, and a third protection layer. The material of the passivation layer is aluminum oxide, and the passivation layer is on the lower surface of the silicon substrate. The material of the first protection layer is silicon oxynitride, and the first protection layer is on a surface of the passivation layer opposite to the silicon substrate. The material of the second protection layer is silicon nitride, and the second protection layer is on a surface of the first protection layer opposite to the passivation layer. The material of the third protection layer is silicon oxynitride or silicon oxide, and the third protection layer is on a surface of the second protection layer opposite to the first protection layer.