A method of fabricating a differential doped solar cell is provided. The method comprises the steps of (a) providing a light doped semiconductor substrate; (b) forming a heavy doped layer having the same type of dopant used in step (a) on a front surface of the semiconductor substrate; and (c) forming an emitter layer having a different type of dopant used in step (a) on a surface of the heavy doped layer to constitute a p-n junction with the heavy doped layer.