NOVELTY - A photovoltaic module (402) comprises elongated substrate (403); one or more solar cells on elongated substrate; filler material (330) on transparent conductive layer (412) of each of the solar cells; and transparent casing (310) on the filler material to seal the photovoltaic module. Each solar cell further comprises back-electrode (404) and semiconductor junction (410). The transparent conductive layer has first refractive index. The filler material has second refractive index that is smaller or equal to the first refractive index. The transparent casing has third refractive index.    USE - Photovoltaic module for a solar cell assembly (claimed).    ADVANTAGE - The transparent casing, filler material, and transparent conductive layer within the photovoltaic module each have indexes of refraction, and the values for first, second, and third refractive indexes are chosen so that light incident on the transparent casing is refracted towards the active layers of the solar cells of the photovoltaic module. The first and second refractive indexes minimize the reflection of light on a surface of the transparent conductive layer.    DETAILED DESCRIPTION - A photovoltaic module (402) comprises an elongated substrate (403) having a rigid portion, a width dimension, and a longitudinal dimension; one or more solar cells disposed on the elongated substrate; a filler material (330) disposed on a transparent conductive layer (412) of each of the solar cells; and a transparent casing (310) disposed on the filler material to seal the photovoltaic module. Each solar cell comprises a back-electrode (404) disposed on a surface of the elongated substrate; a semiconductor junction (410) disposed on all or a portion of a surface of the back-electrode; and a transparent conductive layer disposed on all or a portion of a surface of the semiconductor junction. The transparent conductive layer has a first refractive index. The filler material has a second refractive index that is smaller or equal in value to the first refractive index. The transparent casing has a third refractive index. An INDEPENDENT CLAIM is included for an assembly comprising photovoltaic modules arranged in coplanar rows to form the assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an elongated photovoltaic module with a tubular casing.    Filler material (330)    Photovoltaic module (402)    Elongated substrate (403)    Back-electrode (404)    Semiconductor junction (410)    Transparent conductive layer (412)