Back-side contact solar cell

A method for producing a back-side contact solar cell, wherein a semiconductor substrate of the solar cell comprises a polished or textured back side and a textured front side, wherein the method comprises the steps of:

• applying a first tunnel layer comprising silicon dioxide to a surface of the back side,
• depositing a full-area, highly doped silicon layer of a first polarity on the first tunnel layer, the highly doped silicon layer of the first polarity comprising a first dopant,
• applying a first precursor layer of a second polarity comprising a second dopant on the highly doped silicon layer of the first polarity, wherein concentrations of the first and second dopants in the highly doped silicon layer and the first precursor layer are such that an amount of the second dopant in the first precursor layer is higher than an amount of the first dopant in the highly doped silicon layer,
• selectively laser irradiating regions of the first precursor layer and the highly doped silicon layer to locally produce highly doped base regions in the back side of the semiconductor substrate by overcompensation of the second dopant for the first dopant in the highly doped silicon layer, and
• selectively removing parts of the highly doped silicon layer and the first precursor layer to expose the surface of the back side, including the highly doped base regions and edge regions that (i) separate remaining parts of the highly doped silicon layer and the highly doped base regions and (ii) define a space along the surface of the back side between the highly doped silicon layer and the highly doped base regions.