The application provides a back contact
cell and a preparation method thereof, and relates to the technical field of solar cells. The preparation method of the back contact
cell comprises the following steps: providing a
semiconductor substrate; sequentially preparing a tunneling
oxide layer and an intrinsic
silicon base layer arranged in a stack on the back light surface of the
semiconductor substrate; preparing a first doped
silicon base layer on the intrinsic
silicon base layer; removing the first doped silicon base layer in a first region, so that the intrinsic silicon base layer in the first region is exposed; preparing a second doped silicon base layer on the back light surface; and annealing the intermediate body of the back contact
cell to form an
electron-doped layer, a hole-doped layer, a tunneling junction and a neutral-doped compensation region. According to the application, the intrinsic silicon base layer in the first region is first exposed, and then the second doped silicon base layer is prepared on the back light surface, and then annealing is performed, so that the
electron-doped layer and the hole-doped layer can be formed synchronously, the tunneling junction and the neutral-doped compensation region can be formed, the process flow steps can be reduced, and the risk of conduction of the
electron-doped layer and the hole-doped layer can be reduced.