NOVELTY - The method comprises selecting a photovoltaic cell (300) operable to convert photons to electrons, selecting a light transparent superstrate having a superstrate absorption coefficient and a superstrate refractive index of 1.5, selecting an encapsulant having an encapsulant absorption coefficient and an encapsulant refractive index, and assembling the photovoltaic module using the selected materials. The absorption coefficients of the superstrate and the encapsulant optimize the light reaching the photovoltaic cell.    USE - The method is useful for fabricating a photovoltaic module having a gain in efficiency.    ADVANTAGE - The method is capable of effectively fabricating the photovoltaic module with improved efficiency, durability and mechanical strength, tuned optical properties such as refractive index and absorption coefficient and controlled refractive index mismatch.    DETAILED DESCRIPTION - The method comprises selecting a photovoltaic cell (300) operable to convert photons to electrons, selecting a light transparent superstrate having a superstrate absorption coefficient and a superstrate refractive index of 1.5, selecting an encapsulant having an encapsulant absorption coefficient and an encapsulant refractive index, and assembling the photovoltaic module using the selected materials. The absorption coefficients of the superstrate and the encapsulant optimize the light reaching the photovoltaic cell. The respective refractive indices of the superstrate and the encapsulant are selected such that there is a gain in efficiency, where the optimized gain in efficiency is based in part on escape cone loss and based on short-circuit current density of the photovoltaic cell. The encapsulant refractive index is within plus minus 0.05 of the superstrate refractive index. An INDEPENDENT CLAIM is included for a photovoltaic module with controlled refractive index mismatch.    DESCRIPTION OF DRAWING(S) - The diagram shows a cross-sectional view of a photovoltaic module.    Backsheet (100)    Bottom layer of encapsulant (200)    Photovoltaic cell (300)    Top layer of encapsulant (400)    Light transparent superstate. (500)