NOVELTY - Self aligning method for forming contact metallization in a solar cell comprises coating a surface (41) of a semiconductor substrate (11) with dielectric or surface masking layer(s) (12) containing dopants of opposite polarity to those used in the surface of the substrate. This layer acts or is modifiable in situ to act as a surface passivation layer and/or metallization mask.    USE - For forming contact metallization in a solar cell. The method is particularly applicable in photovoltaic device manufacture.    ADVANTAGE - The method can achieve the same performance as buried contact solar cell on float zone material. On thermally sensitive material that includes many types of commercial grade substrates, the method minimizes the wafer's exposure to high temperatures and reduces the time needed for the thermal processes to lead to a higher performance compared to a buried contact solar cell. Application of the method to the light receiving surface and to the rear surface produces a bifacial solar cell of high performance.    DETAILED DESCRIPTION - Contact metallization in a solar cell by a self aligning method comprises:    (a) coating a surface of a semiconductor substrate of a first dopant polarity with a continuous layer of a dopant source material that is opposite to the dopant polarity of the substrate;    (b) thermally treating the substrate with the dopant source material to form a surface region of the second dopant type on the semiconductor material, the first and second doped semiconductor types forming a p-n junction beneath the surface of the substrate;    (c) locally heating the dopant source material and the underlying semiconductor surface to melt the surface region in zones where metallization is required to contact to the surface region, the melted zones are more heavily doped from the dopant source material and the overlying dopant source material is disrupted to expose the more heavily doped surface regions; and    (d) forming metallization over the heavily doped surface zones such that connection to the surface region of the semiconductor material is made to the heavily doped surface zones through the disruption in the layer of dopant source material. The selected source material acts or is modifiable to act in situ as a surface passivation layer and a metallization pattern mask.    DESCRIPTION OF DRAWING(S) - A cross-section through a partially fabricated solar cell device is shown.    Substrate (11)    Dielectric or surface masking layer (12)    Surface (41)