A solar cell, comprising: a semiconductor substrate; a passivation film on one surface of the semiconductor substrate, the passivation film being formed of a dielectric material; and a semiconductor layer on the passivation film, the semiconductor layer comprising a first conductive region having a first conductive type and a second conductive region having a second conductive type opposite to the first conductive type, wherein the semiconductor substrate further comprises a diffusion region including at least one of a first diffusion region and a second diffusion region adjacent to the passivation film, wherein the first diffusion region is locally formed to correspond to the first conductive region, has dopants of the first conductive type, and has a doping concentration lower than a doping concentration of the first conductive region, wherein the second diffusion region is locally formed to correspond to the second conductive region, has dopants of the second conductive type, and has a doping concentration lower than a doping concentration of the second conductive region, characterized in that the passivation film comprises at least one of a first doped portion locally formed between the first conductive region and the first diffusion region and a second doped portion locally formed between the second conductive region and the second diffusion region, the passivation film is an amorphous film consisting of an amorphous structure or an amorphous film including the amorphous structure and a partially-crystallized portion, and the semiconductor layer has a poly-crystalline structure with a nanometer-sized grain. a semiconductor substrate; a passivation film on one surface of the semiconductor substrate, the passivation film being formed of a dielectric material; and a semiconductor layer on the passivation film, the semiconductor layer comprising a first conductive region having a first conductive type and a second conductive region having a second conductive type opposite to the first conductive type, wherein the semiconductor substrate further comprises a diffusion region including at least one of a first diffusion region and a second diffusion region adjacent to the passivation film, wherein the first diffusion region is locally formed to correspond to the first conductive region, has dopants of the first conductive type, and has a doping concentration lower than a doping concentration of the first conductive region, wherein the second diffusion region is locally formed to correspond to the second conductive region, has dopants of the second conductive type, and has a doping concentration lower than a doping concentration of the second conductive region, characterized in that the passivation film comprises at least one of a first doped portion locally formed between the first conductive region and the first diffusion region and a second doped portion locally formed between the second conductive region and the second diffusion region, the passivation film is an amorphous film consisting of an amorphous structure or an amorphous film including the amorphous structure and a partially-crystallized portion, and the semiconductor layer has a poly-crystalline structure with a nanometer-sized grain.