TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further comprises: depositing the reflective material on the concave surface of the optical element; and mounting a solar cell onto a central region of the convex surface of the optical element so that the solar cell is electrically coupled to the conductive material. In the method, thermal spraying of the conductive material comprises thermal spraying a molten metal powder including at least one of gold, nickel or copper onto the insulative material, where spraying the molten metal powder onto the optical element comprises placing a stencil on the optical element, and spraying the molten metal powder onto the stencil and the insulative material layer. The method further comprises removing the stencil to expose an aperture from which light may pass out of the optical element, and mounting the solar cell comprises positioning the solar cell in the central region of the convex surface so that an optically-active area of the solar cell is aligned with the aperture. In the method, depositing the reflective material comprises depositing a mirror coating using one of sputtering, physical vapor deposition or liquid deposition. In the method, depositing the insulative material comprises depositing a powder-coated polymer using one of spraying, dipping or lamination.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The optical element further includes a concave surface defined in the flat surface, where the convex surface and concave surface are arranged so that the light reflected by the first reflective material disposed on the convex surface is directed towards the concave surface. The stencil comprises a mechanical, hard or soft tooling. The solar concentrator further comprises: the second reflective material layer, and the solar cell. The reflective material is deposited on the concave surface so that the light reflected from the reflective material disposed on the convex surface is re-reflected by the reflective material disposed on the concave surface towards the solar cell. The conductive material layer comprises a molten metal powder containing at least one of gold, nickel or copper. The optical element includes an aperture disposed in a central region of the convex surface from which light may pass out of the optical element. The reflective material layers comprise a mirror coating. The insulative material layer comprises a polymer (preferred) or a powder-coated polymer. EXAMPLE - No suitable example given.