Method, apparatus, and composition of matter suited for use with, for example, immersion lithography. The composition of matter includes hafnium dioxide nanoparticles having diameters less than or equal to about 15 nanometers. The apparatus includes the composition of matter, a light source, a platform for supporting a work piece, and a lens element. The method includes providing a light source, providing a lens element between the light source and a work piece, providing the composition of matter between the lens element and the work piece, and exposing the work piece to light provided by the light source by passing light from the light source through the lens element and the composition of matter to the work piece.