Abstract: Bodies having conical structures with dimensions on the order of the wavelength of visible light are prepared by a specific process. This process involves the formation of a mask by depositing a material that forms the mask onto the body to be etched and choosing the mask material so that it does not substantially wet the surface of the body. The mask thus fabricated has hill-type formations where the spacings between these formations are of the order of the wavelength of visible light. An etchant that etches the mask at a specific rate relative to the underlying body is then used to perform the etching procedure. Exemplary bodies produced by the procedure include tungsten textured bodies that exhibit light emissivities significantly higher than those possessed by the corresponding untreated tungsten material.

Abstract: Materials have been made that exhibit high absorption in the visible, near ultraviolet, and near infrared spectral region while simultaneously exhibiting low absorptivity in the thermal infrared. Exemplary of such materials is silicon which is etched in a reactive sputtering process in the presence of a sputterable material. Other materials exhibiting useful properties are produced by this method.