NOVELTY - The photovoltaic or semiconductor encapsulant comprises a polymeric material, a filler material (0.01-80 mass%) comprising an enhanced particle size distribution, a brightening agent and/or an infrared extinguisher, and a thermal conducting agent. The enhanced particle size distribution comprises a median particle diameter of 0.005-100 micrometers, and a polydispersity of 0-10. A ratio of the brightening agent to the thermal conducting agent is 1-4 on a volumetric basis. The infrared extinguisher reduces a portion of light absorbed by a solar cell.    USE - The photovoltaic or semiconductor encapsulant is useful for laminating, adhering, adjoining, gluing, sealing, caulking and/or joining a portion of semiconductor components, a solar panel, a solar module, a solar array and/or any other suitable assembly.    ADVANTAGE - The photovoltaic or semiconductor encapsulant can be effectively used in solar panels with higher thermal conductivities thus ensuring reliable operation of the solar panels by maintaining sufficient dielectric properties, and has good optical properties such as refractive index and clarity similar to clear glass.    DETAILED DESCRIPTION - The photovoltaic or semiconductor encapsulant comprises a polymeric material, a filler material (0.01-80 mass%) comprising an enhanced particle size distribution, a brightening agent and/or an infrared extinguisher, and a thermal conducting agent. The enhanced particle size distribution comprises a median particle diameter of 0.005-100 micrometers, and a polydispersity of 0-10. A ratio of the brightening agent to the thermal conducting agent is 1-4 on a volumetric basis. The infrared extinguisher reduces a portion of light absorbed by a solar cell comprising a wavelength of greater than 700 nanometers or greater than 1,100 nanometers. The filler material comprises a median particle diameter of 0.1-10 micrometers, and a real part of a refractive index of 1-4. INDEPENDENT CLAIMS are included for:    (1) a photovoltaic or semiconductor back sheet;    (2) a solar module for converting light into electricity; and    (3) a process for making a solar module.    DESCRIPTION OF DRAWING(S) - The diagram shows a cross-sectional view of a solar panel.    Solar panel (10)    Front layer (12)    First encapsulant sheet (14)    Photovoltaic cells (16)    Second encapsulant sheet. (18)