A photovoltaic device and a manufacturing method thereof are provided. The photovoltaic device includes: a substrate; a first conductive layer formed on the substrate; P layers and N layers alternately formed along a first direction on the first conductive layer; and I layers covering the P layers and the N layers on the first conductive layer, wherein the P layers and the N layers are separated from each other by a first interval, the I layers are formed between the P layers and the N layers that are separated by the first interval, and the P layers, the I layers, and the N layers formed along the first direction form unit cells.