NOVELTY - Composition comprises a phase separated block copolymer and an inorganic dielectric nanoparticle. The nanoparticle is dispersed in the copolymer and is present primarily in one phase, where the composition has a selectivity of inorganic dielectric nanoparticle for one block phase over another in a phase-separated block copolymer after the precursor conversion process, of at least 3.    USE - The composition is useful: in an article, which is useful as a light splitting film, a polarizing film, an antireflective film, a reflective film, a band pass filter, a brightness enhancement film, a light re-directing film or a solar heat control film in a photovoltaic device (all claimed) comprising building integrated photovoltaic devices, solar cells or LEDs; and for manufacturing wave guides, patterns, light separating structures, simple or complex lens structures, arrays, gratings, holograms, shoes or packaging.    ADVANTAGE - The composition: achieves modification of the minimum phasic dimension in a selective area relative to the entire article; exhibits improved crystallinity, thus enabling the selective incorporation of the nanoparticles into the soft segments of the olefin block copolymer; can be prepared by low cost, simple, high yielding process; exhibits desired refractive properties, and uniquely selectively incorporated inorganic dielectric material with the appropriate feature size to be optically active in the desired wavelength ranges; provides the filter exhibiting at least 90% transmittance of light of the desired wavelength, low angle and/or variable angle light acceptance as a result of multiple controlled surface textures and/or topographies that result in excellent light capture, a tunable refractive index, heat management via the reflection of undesired wavelengths and UV management; and improves the efficiency of photovoltaic devices.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) an article comprising the composition;    (2) a photovoltaic device, comprising the article; and    (3) preparing the composition, comprises: providing the phase-separated block copolymer; selectively incorporating the inorganic dielectric precursor into one of the phases of the copolymer; converting the precursor into a inorganic dielectric material; and recovering the composition.