A surface region of a semiconductor material on a surface of a semiconductor device is doped during its manufacture, by coating the surface region of the semiconductor material with a dielectric material surface layer and locally heating the surface of the semiconductor material in an area to be doped to locally melt the semiconductor material with the melting being performed in the presence of a dopant source. The heating is performed in a controlled manner such that a region of the surface of the semiconductor material in the area to be doped is maintained in a molten state without refreezing for a period of time greater than one microsecond and the dopant from the dopant source is absorbed into the molten semiconductor. The semiconductor device includes a semiconductor material structure in which a junction is formed and may incorporate a multi-layer anti-reflection coating. The anti-reflection coating is located on a light receiving surface of the semiconductor material structure and comprises a thin layer of thermal expansion mismatch correction material having a thermal expansion coefficient less than or equal to that of the semiconductor material, to provide thermal expansion coefficient mismatch correction. An anti-reflection layer is provided having a refractive index and thickness selected to match the semiconductor material structure so as to give good overall antireflection properties to the solar cell.